// clang-format off
// Ogg Vorbis audio decoder - v1.07 - public domain
// http://nothings.org/stb_vorbis/
//
// Original version written by Sean Barrett in 2007.
//
// Originally sponsored by RAD Game Tools. Seeking sponsored
// by Phillip Bennefall, Marc Andersen, Aaron Baker, Elias Software,
// Aras Pranckevicius, and Sean Barrett.
//
// LICENSE
//
//   This software is in the public domain. Where that dedication is not
//   recognized, you are granted a perpetual, irrevocable license to copy,
//   distribute, and modify this file as you see fit.
//
// No warranty for any purpose is expressed or implied by the author (nor
// by RAD Game Tools). Report bugs and send enhancements to the author.
//
// Limitations:
//
//   - floor 0 not supported (used in old ogg vorbis files pre-2004)
//   - lossless sample-truncation at beginning ignored
//   - cannot concatenate multiple vorbis streams
//   - sample positions are 32-bit, limiting seekable 192Khz
//       files to around 6 hours (Ogg supports 64-bit)
//
// Feature contributors:
//    Dougall Johnson (sample-exact seeking)
//
// Bugfix/warning contributors:
//    Terje Mathisen     Niklas Frykholm     Andy Hill
//    Casey Muratori     John Bolton         Gargaj
//    Laurent Gomila     Marc LeBlanc        Ronny Chevalier
//    Bernhard Wodo      Evan Balster        "alxprd"@github
//    Tom Beaumont       Ingo Leitgeb        Nicolas Guillemot
//    Phillip Bennefall  Rohit
//
// Partial history:
//    1.07    - 2015/01/16 - fixes for crashes on invalid files; warning fixes; const
//    1.06    - 2015/08/31 - full, correct support for seeking API (Dougall Johnson)
//                           some crash fixes when out of memory or with corrupt files
//                           fix some inappropriately signed shifts
//    1.05    - 2015/04/19 - don't define __forceinline if it's redundant
//    1.04    - 2014/08/27 - fix missing const-correct case in API
//    1.03    - 2014/08/07 - warning fixes
//    1.02    - 2014/07/09 - declare qsort comparison as explicitly _cdecl in Windows
//    1.01    - 2014/06/18 - fix stb_vorbis_get_samples_float (interleaved was correct)
//    1.0     - 2014/05/26 - fix memory leaks; fix warnings; fix bugs in >2-channel;
//                           (API change) report sample rate for decode-full-file funcs
//
// See end of file for full version history.


//////////////////////////////////////////////////////////////////////////////
//
//  HEADER BEGINS HERE
//

#ifndef STB_VORBIS_INCLUDE_STB_VORBIS_H
#define STB_VORBIS_INCLUDE_STB_VORBIS_H

#if defined(STB_VORBIS_NO_CRT) && !defined(STB_VORBIS_NO_STDIO)
#define STB_VORBIS_NO_STDIO 1
#endif

#ifndef STB_VORBIS_NO_STDIO
#include <stdio.h>
#endif

#ifdef __cplusplus
extern "C" {
#endif

    ///////////   THREAD SAFETY

    // Individual stb_vorbis* handles are not thread-safe; you cannot decode from
    // them from multiple threads at the same time. However, you can have multiple
    // stb_vorbis* handles and decode from them independently in multiple thrads.


    ///////////   MEMORY ALLOCATION

    // normally stb_vorbis uses malloc() to allocate memory at startup,
    // and alloca() to allocate temporary memory during a frame on the
    // stack. (Memory consumption will depend on the amount of setup
    // data in the file and how you set the compile flags for speed
    // vs. size. In my test files the maximal-size usage is ~150KB.)
    //
    // You can modify the wrapper functions in the source (setup_malloc,
    // setup_temp_malloc, temp_malloc) to change this behavior, or you
    // can use a simpler allocation model: you pass in a buffer from
    // which stb_vorbis will allocate _all_ its memory (including the
    // temp memory). "open" may fail with a VORBIS_outofmem if you
    // do not pass in enough data; there is no way to determine how
    // much you do need except to succeed (at which point you can
    // query get_info to find the exact amount required. yes I know
    // this is lame).
    //
    // If you pass in a non-NULL buffer of the type below, allocation
    // will occur from it as described above. Otherwise just pass NULL
    // to use malloc()/alloca()

    typedef struct
    {
        char *alloc_buffer;
        int   alloc_buffer_length_in_bytes;
    } stb_vorbis_alloc;


    ///////////   FUNCTIONS USEABLE WITH ALL INPUT MODES

    typedef struct stb_vorbis stb_vorbis;

    typedef struct
    {
        unsigned int sample_rate;
        int channels;

        unsigned int setup_memory_required;
        unsigned int setup_temp_memory_required;
        unsigned int temp_memory_required;

        int max_frame_size;
    } stb_vorbis_info;

    // get general information about the file
    extern stb_vorbis_info stb_vorbis_get_info(stb_vorbis *f);

    // get the last error detected (clears it, too)
    extern int stb_vorbis_get_error(stb_vorbis *f);

    // close an ogg vorbis file and free all memory in use
    extern void stb_vorbis_close(stb_vorbis *f);

    // this function returns the offset (in samples) from the beginning of the
    // file that will be returned by the next decode, if it is known, or -1
    // otherwise. after a flush_pushdata() call, this may take a while before
    // it becomes valid again.
    // NOT WORKING YET after a seek with PULLDATA API
    extern int stb_vorbis_get_sample_offset(stb_vorbis *f);

    // returns the current seek point within the file, or offset from the beginning
    // of the memory buffer. In pushdata mode it returns 0.
    extern unsigned int stb_vorbis_get_file_offset(stb_vorbis *f);

    ///////////   PUSHDATA API

#ifndef STB_VORBIS_NO_PUSHDATA_API

    // this API allows you to get blocks of data from any source and hand
    // them to stb_vorbis. you have to buffer them; stb_vorbis will tell
    // you how much it used, and you have to give it the rest next time;
    // and stb_vorbis may not have enough data to work with and you will
    // need to give it the same data again PLUS more. Note that the Vorbis
    // specification does not bound the size of an individual frame.

    extern stb_vorbis *stb_vorbis_open_pushdata(
        const unsigned char * datablock, int datablock_length_in_bytes,
        int *datablock_memory_consumed_in_bytes,
        int *error,
        const stb_vorbis_alloc *alloc_buffer);
    // create a vorbis decoder by passing in the initial data block containing
    //    the ogg&vorbis headers (you don't need to do parse them, just provide
    //    the first N bytes of the file--you're told if it's not enough, see below)
    // on success, returns an stb_vorbis *, does not set error, returns the amount of
    //    data parsed/consumed on this call in *datablock_memory_consumed_in_bytes;
    // on failure, returns NULL on error and sets *error, does not change *datablock_memory_consumed
    // if returns NULL and *error is VORBIS_need_more_data, then the input block was
    //       incomplete and you need to pass in a larger block from the start of the file

    extern int stb_vorbis_decode_frame_pushdata(
        stb_vorbis *f,
        const unsigned char *datablock, int datablock_length_in_bytes,
        int *channels,             // place to write number of float * buffers
        float ***output,           // place to write float ** array of float * buffers
        int *samples               // place to write number of output samples
        );
    // decode a frame of audio sample data if possible from the passed-in data block
    //
    // return value: number of bytes we used from datablock
    //
    // possible cases:
    //     0 bytes used, 0 samples output (need more data)
    //     N bytes used, 0 samples output (resynching the stream, keep going)
    //     N bytes used, M samples output (one frame of data)
    // note that after opening a file, you will ALWAYS get one N-bytes,0-sample
    // frame, because Vorbis always "discards" the first frame.
    //
    // Note that on resynch, stb_vorbis will rarely consume all of the buffer,
    // instead only datablock_length_in_bytes-3 or less. This is because it wants
    // to avoid missing parts of a page header if they cross a datablock boundary,
    // without writing state-machiney code to record a partial detection.
    //
    // The number of channels returned are stored in *channels (which can be
    // NULL--it is always the same as the number of channels reported by
    // get_info). *output will contain an array of float* buffers, one per
    // channel. In other words, (*output)[0][0] contains the first sample from
    // the first channel, and (*output)[1][0] contains the first sample from
    // the second channel.

    extern void stb_vorbis_flush_pushdata(stb_vorbis *f);
    // inform stb_vorbis that your next datablock will not be contiguous with
    // previous ones (e.g. you've seeked in the data); future attempts to decode
    // frames will cause stb_vorbis to resynchronize (as noted above), and
    // once it sees a valid Ogg page (typically 4-8KB, as large as 64KB), it
    // will begin decoding the _next_ frame.
    //
    // if you want to seek using pushdata, you need to seek in your file, then
    // call stb_vorbis_flush_pushdata(), then start calling decoding, then once
    // decoding is returning you data, call stb_vorbis_get_sample_offset, and
    // if you don't like the result, seek your file again and repeat.
#endif


    //////////   PULLING INPUT API

#ifndef STB_VORBIS_NO_PULLDATA_API
    // This API assumes stb_vorbis is allowed to pull data from a source--
    // either a block of memory containing the _entire_ vorbis stream, or a
    // FILE * that you or it create, or possibly some other reading mechanism
    // if you go modify the source to replace the FILE * case with some kind
    // of callback to your code. (But if you don't support seeking, you may
    // just want to go ahead and use pushdata.)

#if !defined(STB_VORBIS_NO_STDIO) && !defined(STB_VORBIS_NO_INTEGER_CONVERSION)
    extern int stb_vorbis_decode_filename(const char *filename, int *channels, int *sample_rate, short **output);
#endif
#if !defined(STB_VORBIS_NO_INTEGER_CONVERSION)
    extern int stb_vorbis_decode_memory(const unsigned char *mem, int len, int *channels, int *sample_rate, short **output);
#endif
    // decode an entire file and output the data interleaved into a malloc()ed
    // buffer stored in *output. The return value is the number of samples
    // decoded, or -1 if the file could not be opened or was not an ogg vorbis file.
    // When you're done with it, just free() the pointer returned in *output.

    extern stb_vorbis * stb_vorbis_open_memory(const unsigned char *data, int len,
        int *error, const stb_vorbis_alloc *alloc_buffer);
    // create an ogg vorbis decoder from an ogg vorbis stream in memory (note
    // this must be the entire stream!). on failure, returns NULL and sets *error

#ifndef STB_VORBIS_NO_STDIO
    extern stb_vorbis * stb_vorbis_open_filename(const char *filename,
        int *error, const stb_vorbis_alloc *alloc_buffer);
    // create an ogg vorbis decoder from a filename via fopen(). on failure,
    // returns NULL and sets *error (possibly to VORBIS_file_open_failure).

    extern stb_vorbis * stb_vorbis_open_file(FILE *f, int close_handle_on_close,
        int *error, const stb_vorbis_alloc *alloc_buffer);
    // create an ogg vorbis decoder from an open FILE *, looking for a stream at
    // the _current_ seek point (ftell). on failure, returns NULL and sets *error.
    // note that stb_vorbis must "own" this stream; if you seek it in between
    // calls to stb_vorbis, it will become confused. Morever, if you attempt to
    // perform stb_vorbis_seek_*() operations on this file, it will assume it
    // owns the _entire_ rest of the file after the start point. Use the next
    // function, stb_vorbis_open_file_section(), to limit it.

    extern stb_vorbis * stb_vorbis_open_file_section(FILE *f, int close_handle_on_close,
        int *error, const stb_vorbis_alloc *alloc_buffer, unsigned int len);
    // create an ogg vorbis decoder from an open FILE *, looking for a stream at
    // the _current_ seek point (ftell); the stream will be of length 'len' bytes.
    // on failure, returns NULL and sets *error. note that stb_vorbis must "own"
    // this stream; if you seek it in between calls to stb_vorbis, it will become
    // confused.
#endif

    extern int stb_vorbis_seek_frame(stb_vorbis *f, unsigned int sample_number);
    extern int stb_vorbis_seek(stb_vorbis *f, unsigned int sample_number);
    // these functions seek in the Vorbis file to (approximately) 'sample_number'.
    // after calling seek_frame(), the next call to get_frame_*() will include
    // the specified sample. after calling stb_vorbis_seek(), the next call to
    // stb_vorbis_get_samples_* will start with the specified sample. If you
    // do not need to seek to EXACTLY the target sample when using get_samples_*,
    // you can also use seek_frame().

    extern void stb_vorbis_seek_start(stb_vorbis *f);
    // this function is equivalent to stb_vorbis_seek(f,0)

    extern unsigned int stb_vorbis_stream_length_in_samples(stb_vorbis *f);
    extern float        stb_vorbis_stream_length_in_seconds(stb_vorbis *f);
    // these functions return the total length of the vorbis stream

    extern int stb_vorbis_get_frame_float(stb_vorbis *f, int *channels, float ***output);
    // decode the next frame and return the number of samples. the number of
    // channels returned are stored in *channels (which can be NULL--it is always
    // the same as the number of channels reported by get_info). *output will
    // contain an array of float* buffers, one per channel. These outputs will
    // be overwritten on the next call to stb_vorbis_get_frame_*.
    //
    // You generally should not intermix calls to stb_vorbis_get_frame_*()
    // and stb_vorbis_get_samples_*(), since the latter calls the former.

#ifndef STB_VORBIS_NO_INTEGER_CONVERSION
    extern int stb_vorbis_get_frame_short_interleaved(stb_vorbis *f, int num_c, short *buffer, int num_shorts);
    extern int stb_vorbis_get_frame_short(stb_vorbis *f, int num_c, short **buffer, int num_samples);
#endif
    // decode the next frame and return the number of *samples* per channel.
    // Note that for interleaved data, you pass in the number of shorts (the
    // size of your array), but the return value is the number of samples per
    // channel, not the total number of samples.
    //
    // The data is coerced to the number of channels you request according to the
    // channel coercion rules (see below). You must pass in the size of your
    // buffer(s) so that stb_vorbis will not overwrite the end of the buffer.
    // The maximum buffer size needed can be gotten from get_info(); however,
    // the Vorbis I specification implies an absolute maximum of 4096 samples
    // per channel.

    // Channel coercion rules:
    //    Let M be the number of channels requested, and N the number of channels present,
    //    and Cn be the nth channel; let stereo L be the sum of all L and center channels,
    //    and stereo R be the sum of all R and center channels (channel assignment from the
    //    vorbis spec).
    //        M    N       output
    //        1    k      sum(Ck) for all k
    //        2    *      stereo L, stereo R
    //        k    l      k > l, the first l channels, then 0s
    //        k    l      k <= l, the first k channels
    //    Note that this is not _good_ surround etc. mixing at all! It's just so
    //    you get something useful.

    extern int stb_vorbis_get_samples_float_interleaved(stb_vorbis *f, int channels, float *buffer, int num_floats);
    extern int stb_vorbis_get_samples_float(stb_vorbis *f, int channels, float **buffer, int num_samples);
    // gets num_samples samples, not necessarily on a frame boundary--this requires
    // buffering so you have to supply the buffers. DOES NOT APPLY THE COERCION RULES.
    // Returns the number of samples stored per channel; it may be less than requested
    // at the end of the file. If there are no more samples in the file, returns 0.

#ifndef STB_VORBIS_NO_INTEGER_CONVERSION
    extern int stb_vorbis_get_samples_short_interleaved(stb_vorbis *f, int channels, short *buffer, int num_shorts);
    extern int stb_vorbis_get_samples_short(stb_vorbis *f, int channels, short **buffer, int num_samples);
#endif
    // gets num_samples samples, not necessarily on a frame boundary--this requires
    // buffering so you have to supply the buffers. Applies the coercion rules above
    // to produce 'channels' channels. Returns the number of samples stored per channel;
    // it may be less than requested at the end of the file. If there are no more
    // samples in the file, returns 0.

#endif

    ////////   ERROR CODES

    enum STBVorbisError
    {
        VORBIS__no_error,

        VORBIS_need_more_data = 1,             // not a real error

        VORBIS_invalid_api_mixing,           // can't mix API modes
        VORBIS_outofmem,                     // not enough memory
        VORBIS_feature_not_supported,        // uses floor 0
        VORBIS_too_many_channels,            // STB_VORBIS_MAX_CHANNELS is too small
        VORBIS_file_open_failure,            // fopen() failed
        VORBIS_seek_without_length,          // can't seek in unknown-length file

        VORBIS_unexpected_eof = 10,            // file is truncated?
        VORBIS_seek_invalid,                 // seek past EOF

                                             // decoding errors (corrupt/invalid stream) -- you probably
                                             // don't care about the exact details of these

                                             // vorbis errors:
        VORBIS_invalid_setup = 20,
        VORBIS_invalid_stream,

        // ogg errors:
        VORBIS_missing_capture_pattern = 30,
        VORBIS_invalid_stream_structure_version,
        VORBIS_continued_packet_flag_invalid,
        VORBIS_incorrect_stream_serial_number,
        VORBIS_invalid_first_page,
        VORBIS_bad_packet_type,
        VORBIS_cant_find_last_page,
        VORBIS_seek_failed
    };


#ifdef __cplusplus
}
#endif

#endif // STB_VORBIS_INCLUDE_STB_VORBIS_H
//
//  HEADER ENDS HERE
//
//////////////////////////////////////////////////////////////////////////////

#ifndef STB_VORBIS_HEADER_ONLY

// global configuration settings (e.g. set these in the project/makefile),
// or just set them in this file at the top (although ideally the first few
// should be visible when the header file is compiled too, although it's not
// crucial)

// STB_VORBIS_NO_PUSHDATA_API
//     does not compile the code for the various stb_vorbis_*_pushdata()
//     functions
// #define STB_VORBIS_NO_PUSHDATA_API

// STB_VORBIS_NO_PULLDATA_API
//     does not compile the code for the non-pushdata APIs
// #define STB_VORBIS_NO_PULLDATA_API

// STB_VORBIS_NO_STDIO
//     does not compile the code for the APIs that use FILE *s internally
//     or externally (implied by STB_VORBIS_NO_PULLDATA_API)
// #define STB_VORBIS_NO_STDIO

// STB_VORBIS_NO_INTEGER_CONVERSION
//     does not compile the code for converting audio sample data from
//     float to integer (implied by STB_VORBIS_NO_PULLDATA_API)
// #define STB_VORBIS_NO_INTEGER_CONVERSION

// STB_VORBIS_NO_FAST_SCALED_FLOAT
//      does not use a fast float-to-int trick to accelerate float-to-int on
//      most platforms which requires endianness be defined correctly.
//#define STB_VORBIS_NO_FAST_SCALED_FLOAT


// STB_VORBIS_MAX_CHANNELS [number]
//     globally define this to the maximum number of channels you need.
//     The spec does not put a restriction on channels except that
//     the count is stored in a byte, so 255 is the hard limit.
//     Reducing this saves about 16 bytes per value, so using 16 saves
//     (255-16)*16 or around 4KB. Plus anything other memory usage
//     I forgot to account for. Can probably go as low as 8 (7.1 audio),
//     6 (5.1 audio), or 2 (stereo only).
#ifndef STB_VORBIS_MAX_CHANNELS
#define STB_VORBIS_MAX_CHANNELS    16  // enough for anyone?
#endif

// STB_VORBIS_PUSHDATA_CRC_COUNT [number]
//     after a flush_pushdata(), stb_vorbis begins scanning for the
//     next valid page, without backtracking. when it finds something
//     that looks like a page, it streams through it and verifies its
//     CRC32. Should that validation fail, it keeps scanning. But it's
//     possible that _while_ streaming through to check the CRC32 of
//     one candidate page, it sees another candidate page. This #define
//     determines how many "overlapping" candidate pages it can search
//     at once. Note that "real" pages are typically ~4KB to ~8KB, whereas
//     garbage pages could be as big as 64KB, but probably average ~16KB.
//     So don't hose ourselves by scanning an apparent 64KB page and
//     missing a ton of real ones in the interim; so minimum of 2
#ifndef STB_VORBIS_PUSHDATA_CRC_COUNT
#define STB_VORBIS_PUSHDATA_CRC_COUNT  4
#endif

// STB_VORBIS_FAST_HUFFMAN_LENGTH [number]
//     sets the log size of the huffman-acceleration table.  Maximum
//     supported value is 24. with larger numbers, more decodings are O(1),
//     but the table size is larger so worse cache missing, so you'll have
//     to probe (and try multiple ogg vorbis files) to find the sweet spot.
#ifndef STB_VORBIS_FAST_HUFFMAN_LENGTH
#define STB_VORBIS_FAST_HUFFMAN_LENGTH   10
#endif

// STB_VORBIS_FAST_BINARY_LENGTH [number]
//     sets the log size of the binary-search acceleration table. this
//     is used in similar fashion to the fast-huffman size to set initial
//     parameters for the binary search

// STB_VORBIS_FAST_HUFFMAN_INT
//     The fast huffman tables are much more efficient if they can be
//     stored as 16-bit results instead of 32-bit results. This restricts
//     the codebooks to having only 65535 possible outcomes, though.
//     (At least, accelerated by the huffman table.)
#ifndef STB_VORBIS_FAST_HUFFMAN_INT
#define STB_VORBIS_FAST_HUFFMAN_SHORT
#endif

// STB_VORBIS_NO_HUFFMAN_BINARY_SEARCH
//     If the 'fast huffman' search doesn't succeed, then stb_vorbis falls
//     back on binary searching for the correct one. This requires storing
//     extra tables with the huffman codes in sorted order. Defining this
//     symbol trades off space for speed by forcing a linear search in the
//     non-fast case, except for "sparse" codebooks.
// #define STB_VORBIS_NO_HUFFMAN_BINARY_SEARCH

// STB_VORBIS_DIVIDES_IN_RESIDUE
//     stb_vorbis precomputes the result of the scalar residue decoding
//     that would otherwise require a divide per chunk. you can trade off
//     space for time by defining this symbol.
// #define STB_VORBIS_DIVIDES_IN_RESIDUE

// STB_VORBIS_DIVIDES_IN_CODEBOOK
//     vorbis VQ codebooks can be encoded two ways: with every case explicitly
//     stored, or with all elements being chosen from a small range of values,
//     and all values possible in all elements. By default, stb_vorbis expands
//     this latter kind out to look like the former kind for ease of decoding,
//     because otherwise an integer divide-per-vector-element is required to
//     unpack the index. If you define STB_VORBIS_DIVIDES_IN_CODEBOOK, you can
//     trade off storage for speed.
//#define STB_VORBIS_DIVIDES_IN_CODEBOOK

#ifdef STB_VORBIS_CODEBOOK_SHORTS
#error "STB_VORBIS_CODEBOOK_SHORTS is no longer supported as it produced incorrect results for some input formats"
#endif

// STB_VORBIS_DIVIDE_TABLE
//     this replaces small integer divides in the floor decode loop with
//     table lookups. made less than 1% difference, so disabled by default.

// STB_VORBIS_NO_INLINE_DECODE
//     disables the inlining of the scalar codebook fast-huffman decode.
//     might save a little codespace; useful for debugging
// #define STB_VORBIS_NO_INLINE_DECODE

// STB_VORBIS_NO_DEFER_FLOOR
//     Normally we only decode the floor without synthesizing the actual
//     full curve. We can instead synthesize the curve immediately. This
//     requires more memory and is very likely slower, so I don't think
//     you'd ever want to do it except for debugging.
// #define STB_VORBIS_NO_DEFER_FLOOR




//////////////////////////////////////////////////////////////////////////////

#ifdef STB_VORBIS_NO_PULLDATA_API
#define STB_VORBIS_NO_INTEGER_CONVERSION
#define STB_VORBIS_NO_STDIO
#endif

#if defined(STB_VORBIS_NO_CRT) && !defined(STB_VORBIS_NO_STDIO)
#define STB_VORBIS_NO_STDIO 1
#endif

#ifndef STB_VORBIS_NO_INTEGER_CONVERSION
#ifndef STB_VORBIS_NO_FAST_SCALED_FLOAT

// only need endianness for fast-float-to-int, which we don't
// use for pushdata

#ifndef STB_VORBIS_BIG_ENDIAN
#define STB_VORBIS_ENDIAN  0
#else
#define STB_VORBIS_ENDIAN  1
#endif

#endif
#endif


#ifndef STB_VORBIS_NO_STDIO
#include <stdio.h>
#endif

#ifndef STB_VORBIS_NO_CRT
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <math.h>
#if !(defined(__APPLE__) || defined(MACOSX) || defined(macintosh) || defined(Macintosh))
#include <malloc.h>
#endif
#else // STB_VORBIS_NO_CRT
#define NULL 0
#define malloc(s)   0
#define free(s)     ((void) 0)
#define realloc(s)  0
#endif // STB_VORBIS_NO_CRT

#include <limits.h>

#ifdef __MINGW32__
// eff you mingw:
//     "fixed":
//         http://sourceforge.net/p/mingw-w64/mailman/message/32882927/
//     "no that broke the build, reverted, who cares about C":
//         http://sourceforge.net/p/mingw-w64/mailman/message/32890381/
#ifdef __forceinline
#undef __forceinline
#endif
#define __forceinline
#elif !defined(_MSC_VER)
#if __GNUC__
#define __forceinline inline
#else
#define __forceinline
#endif
#endif

#if STB_VORBIS_MAX_CHANNELS > 256
#error "Value of STB_VORBIS_MAX_CHANNELS outside of allowed range"
#endif

#if STB_VORBIS_FAST_HUFFMAN_LENGTH > 24
#error "Value of STB_VORBIS_FAST_HUFFMAN_LENGTH outside of allowed range"
#endif


#if 0
#include <crtdbg.h>
#define CHECK(f)   _CrtIsValidHeapPointer(f->channel_buffers[1])
#else
#define CHECK(f)   ((void) 0)
#endif

#define MAX_BLOCKSIZE_LOG  13   // from specification
#define MAX_BLOCKSIZE      (1 << MAX_BLOCKSIZE_LOG)


typedef unsigned char  uint8;
typedef   signed char   int8;
typedef unsigned short uint16;
typedef   signed short  int16;
typedef unsigned int   uint32;
typedef   signed int    int32;

#ifndef TRUE
#define TRUE 1
#define FALSE 0
#endif

typedef float codetype;

// @NOTE
//
// Some arrays below are tagged "//varies", which means it's actually
// a variable-sized piece of data, but rather than malloc I assume it's
// small enough it's better to just allocate it all together with the
// main thing
//
// Most of the variables are specified with the smallest size I could pack
// them into. It might give better performance to make them all full-sized
// integers. It should be safe to freely rearrange the structures or change
// the sizes larger--nothing relies on silently truncating etc., nor the
// order of variables.

#define FAST_HUFFMAN_TABLE_SIZE   (1 << STB_VORBIS_FAST_HUFFMAN_LENGTH)
#define FAST_HUFFMAN_TABLE_MASK   (FAST_HUFFMAN_TABLE_SIZE - 1)

typedef struct
{
    int dimensions, entries;
    uint8 *codeword_lengths;
    float  minimum_value;
    float  delta_value;
    uint8  value_bits;
    uint8  lookup_type;
    uint8  sequence_p;
    uint8  sparse;
    uint32 lookup_values;
    codetype *multiplicands;
    uint32 *codewords;
#ifdef STB_VORBIS_FAST_HUFFMAN_SHORT
    int16  fast_huffman[FAST_HUFFMAN_TABLE_SIZE];
#else
    int32  fast_huffman[FAST_HUFFMAN_TABLE_SIZE];
#endif
    uint32 *sorted_codewords;
    int    *sorted_values;
    int     sorted_entries;
} Codebook;

typedef struct
{
    uint8 order;
    uint16 rate;
    uint16 bark_map_size;
    uint8 amplitude_bits;
    uint8 amplitude_offset;
    uint8 number_of_books;
    uint8 book_list[16]; // varies
} Floor0;

typedef struct
{
    uint8 partitions;
    uint8 partition_class_list[32]; // varies
    uint8 class_dimensions[16]; // varies
    uint8 class_subclasses[16]; // varies
    uint8 class_masterbooks[16]; // varies
    int16 subclass_books[16][8]; // varies
    uint16 Xlist[31 * 8 + 2]; // varies
    uint8 sorted_order[31 * 8 + 2];
    uint8 neighbors[31 * 8 + 2][2];
    uint8 floor1_multiplier;
    uint8 rangebits;
    int values;
} Floor1;

typedef union
{
    Floor0 floor0;
    Floor1 floor1;
} Floor;

typedef struct
{
    uint32 begin, end;
    uint32 part_size;
    uint8 classifications;
    uint8 classbook;
    uint8 **classdata;
    int16(*residue_books)[8];
} Residue;

typedef struct
{
    uint8 magnitude;
    uint8 angle;
    uint8 mux;
} MappingChannel;

typedef struct
{
    uint16 coupling_steps;
    MappingChannel *chan;
    uint8  submaps;
    uint8  submap_floor[15]; // varies
    uint8  submap_residue[15]; // varies
} Mapping;

typedef struct
{
    uint8 blockflag;
    uint8 mapping;
    uint16 windowtype;
    uint16 transformtype;
} Mode;

typedef struct
{
    uint32  goal_crc;    // expected crc if match
    int     bytes_left;  // bytes left in packet
    uint32  crc_so_far;  // running crc
    int     bytes_done;  // bytes processed in _current_ chunk
    uint32  sample_loc;  // granule pos encoded in page
} CRCscan;

typedef struct
{
    uint32 page_start, page_end;
    uint32 last_decoded_sample;
} ProbedPage;

struct stb_vorbis
{
    // user-accessible info
    unsigned int sample_rate;
    int channels;

    unsigned int setup_memory_required;
    unsigned int temp_memory_required;
    unsigned int setup_temp_memory_required;

    // input config
#ifndef STB_VORBIS_NO_STDIO
    FILE *f;
    uint32 f_start;
    int close_on_free;
#endif

    uint8 *stream;
    uint8 *stream_start;
    uint8 *stream_end;

    uint32 stream_len;

    uint8  push_mode;

    uint32 first_audio_page_offset;

    ProbedPage p_first, p_last;

    // memory management
    stb_vorbis_alloc alloc;
    int setup_offset;
    int temp_offset;

    // run-time results
    int eof;
    enum STBVorbisError error;

    // user-useful data

    // header info
    int blocksize[2];
    int blocksize_0, blocksize_1;
    int codebook_count;
    Codebook *codebooks;
    int floor_count;
    uint16 floor_types[64]; // varies
    Floor *floor_config;
    int residue_count;
    uint16 residue_types[64]; // varies
    Residue *residue_config;
    int mapping_count;
    Mapping *mapping;
    int mode_count;
    Mode mode_config[64];  // varies

    uint32 total_samples;

    // decode buffer
    float *channel_buffers[STB_VORBIS_MAX_CHANNELS];
    float *outputs[STB_VORBIS_MAX_CHANNELS];

    float *previous_window[STB_VORBIS_MAX_CHANNELS];
    int previous_length;

#ifndef STB_VORBIS_NO_DEFER_FLOOR
    int16 *finalY[STB_VORBIS_MAX_CHANNELS];
#else
    float *floor_buffers[STB_VORBIS_MAX_CHANNELS];
#endif

    uint32 current_loc; // sample location of next frame to decode
    int    current_loc_valid;

    // per-blocksize precomputed data

    // twiddle factors
    float *A[2], *B[2], *C[2];
    float *window[2];
    uint16 *bit_reverse[2];

    // current page/packet/segment streaming info
    uint32 serial; // stream serial number for verification
    int last_page;
    int segment_count;
    uint8 segments[255];
    uint8 page_flag;
    uint8 bytes_in_seg;
    uint8 first_decode;
    int next_seg;
    int last_seg;  // flag that we're on the last segment
    int last_seg_which; // what was the segment number of the last seg?
    uint32 acc;
    int valid_bits;
    int packet_bytes;
    int end_seg_with_known_loc;
    uint32 known_loc_for_packet;
    int discard_samples_deferred;
    uint32 samples_output;

    // push mode scanning
    int page_crc_tests; // only in push_mode: number of tests active; -1 if not searching
#ifndef STB_VORBIS_NO_PUSHDATA_API
    CRCscan scan[STB_VORBIS_PUSHDATA_CRC_COUNT];
#endif

    // sample-access
    int channel_buffer_start;
    int channel_buffer_end;
};

#if defined(STB_VORBIS_NO_PUSHDATA_API)
#define IS_PUSH_MODE(f)   FALSE
#elif defined(STB_VORBIS_NO_PULLDATA_API)
#define IS_PUSH_MODE(f)   TRUE
#else
#define IS_PUSH_MODE(f)   ((f)->push_mode)
#endif

typedef struct stb_vorbis vorb;

static int error(vorb *f, enum STBVorbisError e)
{
    f->error = e;
    if (!f->eof && e != VORBIS_need_more_data) {
        f->error = e; // breakpoint for debugging
    }
    return 0;
}


// these functions are used for allocating temporary memory
// while decoding. if you can afford the stack space, use
// alloca(); otherwise, provide a temp buffer and it will
// allocate out of those.

#define array_size_required(count,size)  (count*(sizeof(void *)+(size)))

#define temp_alloc(f,size)              (f->alloc.alloc_buffer ? setup_temp_malloc(f,size) : alloca(size))
#ifdef dealloca
#define temp_free(f,p)                  (f->alloc.alloc_buffer ? 0 : dealloca(size))
#else
#define temp_free(f,p)                  0
#endif
#define temp_alloc_save(f)              ((f)->temp_offset)
#define temp_alloc_restore(f,p)         ((f)->temp_offset = (p))

#define temp_block_array(f,count,size)  make_block_array(temp_alloc(f,array_size_required(count,size)), count, size)

// given a sufficiently large block of memory, make an array of pointers to subblocks of it
static void *make_block_array(void *mem, int count, int size)
{
    int i;
    void ** p = (void **)mem;
    char *q = (char *)(p + count);
    for (i = 0; i < count; ++i) {
        p[i] = q;
        q += size;
    }
    return p;
}

static void *setup_malloc(vorb *f, int sz)
{
    sz = (sz + 3) & ~3;
    f->setup_memory_required += sz;
    if (f->alloc.alloc_buffer) {
        void *p = (char *)f->alloc.alloc_buffer + f->setup_offset;
        if (f->setup_offset + sz > f->temp_offset) return NULL;
        f->setup_offset += sz;
        return p;
    }
    return sz ? malloc(sz) : NULL;
}

static void setup_free(vorb *f, void *p)
{
    if (f->alloc.alloc_buffer) return; // do nothing; setup mem is a stack
    free(p);
}

static void *setup_temp_malloc(vorb *f, int sz)
{
    sz = (sz + 3) & ~3;
    if (f->alloc.alloc_buffer) {
        if (f->temp_offset - sz < f->setup_offset) return NULL;
        f->temp_offset -= sz;
        return (char *)f->alloc.alloc_buffer + f->temp_offset;
    }
    return malloc(sz);
}

static void setup_temp_free(vorb *f, void *p, int sz)
{
    if (f->alloc.alloc_buffer) {
        f->temp_offset += (sz + 3)&~3;
        return;
    }
    free(p);
}

#define CRC32_POLY    0x04c11db7   // from spec

static uint32 crc_table[256];
static void crc32_init(void)
{
    int i, j;
    uint32 s;
    for (i = 0; i < 256; i++) {
        for (s = (uint32)i << 24, j = 0; j < 8; ++j)
            s = (s << 1) ^ (s >= (1U << 31) ? CRC32_POLY : 0);
        crc_table[i] = s;
    }
}

static __forceinline uint32 crc32_update(uint32 crc, uint8 byte)
{
    return (crc << 8) ^ crc_table[byte ^ (crc >> 24)];
}


// used in setup, and for huffman that doesn't go fast path
static unsigned int bit_reverse(unsigned int n)
{
    n = ((n & 0xAAAAAAAA) >> 1) | ((n & 0x55555555) << 1);
    n = ((n & 0xCCCCCCCC) >> 2) | ((n & 0x33333333) << 2);
    n = ((n & 0xF0F0F0F0) >> 4) | ((n & 0x0F0F0F0F) << 4);
    n = ((n & 0xFF00FF00) >> 8) | ((n & 0x00FF00FF) << 8);
    return (n >> 16) | (n << 16);
}

static float square(float x)
{
    return x*x;
}

// this is a weird definition of log2() for which log2(1) = 1, log2(2) = 2, log2(4) = 3
// as required by the specification. fast(?) implementation from stb.h
// @OPTIMIZE: called multiple times per-packet with "constants"; move to setup
static int ilog(int32 n)
{
    static signed char log2_4[16] = { 0,1,2,2,3,3,3,3,4,4,4,4,4,4,4,4 };

    // 2 compares if n < 16, 3 compares otherwise (4 if signed or n > 1<<29)
    if (n < (1 << 14))
        if (n < (1 << 4))        return     0 + log2_4[n];
        else if (n < (1 << 9))      return  5 + log2_4[n >> 5];
        else                     return 10 + log2_4[n >> 10];
    else if (n < (1 << 24))
        if (n < (1 << 19))      return 15 + log2_4[n >> 15];
        else                     return 20 + log2_4[n >> 20];
    else if (n < (1 << 29))      return 25 + log2_4[n >> 25];
    else if (n < (1 << 31)) return 30 + log2_4[n >> 30];
    else                return 0; // signed n returns 0
}

#ifndef M_PI
#define M_PI  3.14159265358979323846264f  // from CRC
#endif

// code length assigned to a value with no huffman encoding
#define NO_CODE   255

/////////////////////// LEAF SETUP FUNCTIONS //////////////////////////
//
// these functions are only called at setup, and only a few times
// per file

static float float32_unpack(uint32 x)
{
    // from the specification
    uint32 mantissa = x & 0x1fffff;
    uint32 sign = x & 0x80000000;
    uint32 exp = (x & 0x7fe00000) >> 21;
    double res = sign ? -(double)mantissa : (double)mantissa;
    return (float)ldexp((float)res, exp - 788);
}


// zlib & jpeg huffman tables assume that the output symbols
// can either be arbitrarily arranged, or have monotonically
// increasing frequencies--they rely on the lengths being sorted;
// this makes for a very simple generation algorithm.
// vorbis allows a huffman table with non-sorted lengths. This
// requires a more sophisticated construction, since symbols in
// order do not map to huffman codes "in order".
static void add_entry(Codebook *c, uint32 huff_code, int symbol, int count, int len, uint32 *values)
{
    if (!c->sparse) {
        c->codewords[symbol] = huff_code;
    }
    else {
        c->codewords[count] = huff_code;
        c->codeword_lengths[count] = len;
        values[count] = symbol;
    }
}

static int compute_codewords(Codebook *c, uint8 *len, int n, uint32 *values)
{
    int i, k, m = 0;
    uint32 available[32];

    memset(available, 0, sizeof(available));
    // find the first entry
    for (k = 0; k < n; ++k) if (len[k] < NO_CODE) break;
    if (k == n) { assert(c->sorted_entries == 0); return TRUE; }
    // add to the list
    add_entry(c, 0, k, m++, len[k], values);
    // add all available leaves
    for (i = 1; i <= len[k]; ++i)
        available[i] = 1U << (32 - i);
    // note that the above code treats the first case specially,
    // but it's really the same as the following code, so they
    // could probably be combined (except the initial code is 0,
    // and I use 0 in available[] to mean 'empty')
    for (i = k + 1; i < n; ++i) {
        uint32 res;
        int z = len[i], y;
        if (z == NO_CODE) continue;
        // find lowest available leaf (should always be earliest,
        // which is what the specification calls for)
        // note that this property, and the fact we can never have
        // more than one free leaf at a given level, isn't totally
        // trivial to prove, but it seems true and the assert never
        // fires, so!
        while (z > 0 && !available[z]) --z;
        if (z == 0) { return FALSE; }
        res = available[z];
        assert(z >= 0 && z < 32);
        available[z] = 0;
        add_entry(c, bit_reverse(res), i, m++, len[i], values);
        // propogate availability up the tree
        if (z != len[i]) {
            assert(len[i] >= 0 && len[i] < 32);
            for (y = len[i]; y > z; --y) {
                assert(available[y] == 0);
                available[y] = res + (1 << (32 - y));
            }
        }
    }
    return TRUE;
}

// accelerated huffman table allows fast O(1) match of all symbols
// of length <= STB_VORBIS_FAST_HUFFMAN_LENGTH
static void compute_accelerated_huffman(Codebook *c)
{
    int i, len;
    for (i = 0; i < FAST_HUFFMAN_TABLE_SIZE; ++i)
        c->fast_huffman[i] = -1;

    len = c->sparse ? c->sorted_entries : c->entries;
#ifdef STB_VORBIS_FAST_HUFFMAN_SHORT
    if (len > 32767) len = 32767; // largest possible value we can encode!
#endif
    for (i = 0; i < len; ++i) {
        if (c->codeword_lengths[i] <= STB_VORBIS_FAST_HUFFMAN_LENGTH) {
            uint32 z = c->sparse ? bit_reverse(c->sorted_codewords[i]) : c->codewords[i];
            // set table entries for all bit combinations in the higher bits
            while (z < FAST_HUFFMAN_TABLE_SIZE) {
                c->fast_huffman[z] = i;
                z += 1 << c->codeword_lengths[i];
            }
        }
    }
}

#if defined(_MSC_VER) && defined(_M_IX86)
#define STBV_CDECL __cdecl
#else
#define STBV_CDECL
#endif

static int STBV_CDECL uint32_compare(const void *p, const void *q)
{
    uint32 x = *(uint32 *)p;
    uint32 y = *(uint32 *)q;
    return x < y ? -1 : x > y;
}

static int include_in_sort(Codebook *c, uint8 len)
{
    if (c->sparse) { assert(len != NO_CODE); return TRUE; }
    if (len == NO_CODE) return FALSE;
    if (len > STB_VORBIS_FAST_HUFFMAN_LENGTH) return TRUE;
    return FALSE;
}

// if the fast table above doesn't work, we want to binary
// search them... need to reverse the bits
static void compute_sorted_huffman(Codebook *c, uint8 *lengths, uint32 *values)
{
    int i, len;
    // build a list of all the entries
    // OPTIMIZATION: don't include the short ones, since they'll be caught by FAST_HUFFMAN.
    // this is kind of a frivolous optimization--I don't see any performance improvement,
    // but it's like 4 extra lines of code, so.
    if (!c->sparse) {
        int k = 0;
        for (i = 0; i < c->entries; ++i)
            if (include_in_sort(c, lengths[i]))
                c->sorted_codewords[k++] = bit_reverse(c->codewords[i]);
        assert(k == c->sorted_entries);
    }
    else {
        for (i = 0; i < c->sorted_entries; ++i)
            c->sorted_codewords[i] = bit_reverse(c->codewords[i]);
    }

    qsort(c->sorted_codewords, c->sorted_entries, sizeof(c->sorted_codewords[0]), uint32_compare);
    c->sorted_codewords[c->sorted_entries] = 0xffffffff;

    len = c->sparse ? c->sorted_entries : c->entries;
    // now we need to indicate how they correspond; we could either
    //   #1: sort a different data structure that says who they correspond to
    //   #2: for each sorted entry, search the original list to find who corresponds
    //   #3: for each original entry, find the sorted entry
    // #1 requires extra storage, #2 is slow, #3 can use binary search!
    for (i = 0; i < len; ++i) {
        int huff_len = c->sparse ? lengths[values[i]] : lengths[i];
        if (include_in_sort(c, huff_len)) {
            uint32 code = bit_reverse(c->codewords[i]);
            int x = 0, n = c->sorted_entries;
            while (n > 1) {
                // invariant: sc[x] <= code < sc[x+n]
                int m = x + (n >> 1);
                if (c->sorted_codewords[m] <= code) {
                    x = m;
                    n -= (n >> 1);
                }
                else {
                    n >>= 1;
                }
            }
            assert(c->sorted_codewords[x] == code);
            if (c->sparse) {
                c->sorted_values[x] = values[i];
                c->codeword_lengths[x] = huff_len;
            }
            else {
                c->sorted_values[x] = i;
            }
        }
    }
}

// only run while parsing the header (3 times)
static int vorbis_validate(uint8 *data)
{
    static uint8 vorbis[6] = { 'v', 'o', 'r', 'b', 'i', 's' };
    return memcmp(data, vorbis, 6) == 0;
}

// called from setup only, once per code book
// (formula implied by specification)
static int lookup1_values(int entries, int dim)
{
    int r = (int)floor(exp((float)log((float)entries) / dim));
    if ((int)floor(pow((float)r + 1, dim)) <= entries)   // (int) cast for MinGW warning;
        ++r;                                              // floor() to avoid _ftol() when non-CRT
    assert(pow((float)r + 1, dim) > entries);
    assert((int)floor(pow((float)r, dim)) <= entries); // (int),floor() as above
    return r;
}

// called twice per file
static void compute_twiddle_factors(int n, float *A, float *B, float *C)
{
    int n4 = n >> 2, n8 = n >> 3;
    int k, k2;

    for (k = k2 = 0; k < n4; ++k, k2 += 2) {
        A[k2] = (float)cos(4 * k*M_PI / n);
        A[k2 + 1] = (float)-sin(4 * k*M_PI / n);
        B[k2] = (float)cos((k2 + 1)*M_PI / n / 2) * 0.5f;
        B[k2 + 1] = (float)sin((k2 + 1)*M_PI / n / 2) * 0.5f;
    }
    for (k = k2 = 0; k < n8; ++k, k2 += 2) {
        C[k2] = (float)cos(2 * (k2 + 1)*M_PI / n);
        C[k2 + 1] = (float)-sin(2 * (k2 + 1)*M_PI / n);
    }
}

static void compute_window(int n, float *window)
{
    int n2 = n >> 1, i;
    for (i = 0; i < n2; ++i)
        window[i] = (float)sin(0.5 * M_PI * square((float)sin((i - 0 + 0.5) / n2 * 0.5 * M_PI)));
}

static void compute_bitreverse(int n, uint16 *rev)
{
    int ld = ilog(n) - 1; // ilog is off-by-one from normal definitions
    int i, n8 = n >> 3;
    for (i = 0; i < n8; ++i)
        rev[i] = (bit_reverse(i) >> (32 - ld + 3)) << 2;
}

static int init_blocksize(vorb *f, int b, int n)
{
    int n2 = n >> 1, n4 = n >> 2, n8 = n >> 3;
    f->A[b] = (float *)setup_malloc(f, sizeof(float) * n2);
    f->B[b] = (float *)setup_malloc(f, sizeof(float) * n2);
    f->C[b] = (float *)setup_malloc(f, sizeof(float) * n4);
    if (!f->A[b] || !f->B[b] || !f->C[b]) return error(f, VORBIS_outofmem);
    compute_twiddle_factors(n, f->A[b], f->B[b], f->C[b]);
    f->window[b] = (float *)setup_malloc(f, sizeof(float) * n2);
    if (!f->window[b]) return error(f, VORBIS_outofmem);
    compute_window(n, f->window[b]);
    f->bit_reverse[b] = (uint16 *)setup_malloc(f, sizeof(uint16) * n8);
    if (!f->bit_reverse[b]) return error(f, VORBIS_outofmem);
    compute_bitreverse(n, f->bit_reverse[b]);
    return TRUE;
}

static void neighbors(uint16 *x, int n, int *plow, int *phigh)
{
    int low = -1;
    int high = 65536;
    int i;
    for (i = 0; i < n; ++i) {
        if (x[i] > low  && x[i] < x[n]) { *plow = i; low = x[i]; }
        if (x[i] < high && x[i] > x[n]) { *phigh = i; high = x[i]; }
    }
}

// this has been repurposed so y is now the original index instead of y
typedef struct
{
    uint16 x, y;
} Point;

static int STBV_CDECL point_compare(const void *p, const void *q)
{
    Point *a = (Point *)p;
    Point *b = (Point *)q;
    return a->x < b->x ? -1 : a->x > b->x;
}

//
/////////////////////// END LEAF SETUP FUNCTIONS //////////////////////////


#if defined(STB_VORBIS_NO_STDIO)
#define USE_MEMORY(z)    TRUE
#else
#define USE_MEMORY(z)    ((z)->stream)
#endif

static uint8 get8(vorb *z)
{
    if (USE_MEMORY(z)) {
        if (z->stream >= z->stream_end) { z->eof = TRUE; return 0; }
        return *z->stream++;
    }

#ifndef STB_VORBIS_NO_STDIO
    {
        int c = fgetc(z->f);
        if (c == EOF) { z->eof = TRUE; return 0; }
        return c;
    }
#endif
}

static uint32 get32(vorb *f)
{
    uint32 x;
    x = get8(f);
    x += get8(f) << 8;
    x += get8(f) << 16;
    x += (uint32)get8(f) << 24;
    return x;
}

static int getn(vorb *z, uint8 *data, int n)
{
    if (USE_MEMORY(z)) {
        if (z->stream + n > z->stream_end) { z->eof = 1; return 0; }
        memcpy(data, z->stream, n);
        z->stream += n;
        return 1;
    }

#ifndef STB_VORBIS_NO_STDIO   
    if (fread(data, n, 1, z->f) == 1)
        return 1;
    else {
        z->eof = 1;
        return 0;
    }
#endif
}

static void skip(vorb *z, int n)
{
    if (USE_MEMORY(z)) {
        z->stream += n;
        if (z->stream >= z->stream_end) z->eof = 1;
        return;
    }
#ifndef STB_VORBIS_NO_STDIO
    {
        long x = ftell(z->f);
        fseek(z->f, x + n, SEEK_SET);
    }
#endif
}

static int set_file_offset(stb_vorbis *f, unsigned int loc)
{
#ifndef STB_VORBIS_NO_PUSHDATA_API
    if (f->push_mode) return 0;
#endif
    f->eof = 0;
    if (USE_MEMORY(f)) {
        if (f->stream_start + loc >= f->stream_end || f->stream_start + loc < f->stream_start) {
            f->stream = f->stream_end;
            f->eof = 1;
            return 0;
        }
        else {
            f->stream = f->stream_start + loc;
            return 1;
        }
    }
#ifndef STB_VORBIS_NO_STDIO
    if (loc + f->f_start < loc || loc >= 0x80000000) {
        loc = 0x7fffffff;
        f->eof = 1;
    }
    else {
        loc += f->f_start;
    }
    if (!fseek(f->f, loc, SEEK_SET))
        return 1;
    f->eof = 1;
    fseek(f->f, f->f_start, SEEK_END);
    return 0;
#endif
}


static uint8 ogg_page_header[4] = { 0x4f, 0x67, 0x67, 0x53 };

static int capture_pattern(vorb *f)
{
    if (0x4f != get8(f)) return FALSE;
    if (0x67 != get8(f)) return FALSE;
    if (0x67 != get8(f)) return FALSE;
    if (0x53 != get8(f)) return FALSE;
    return TRUE;
}

#define PAGEFLAG_continued_packet   1
#define PAGEFLAG_first_page         2
#define PAGEFLAG_last_page          4

static int start_page_no_capturepattern(vorb *f)
{
    uint32 loc0, loc1, n;
    // stream structure version
    if (0 != get8(f)) return error(f, VORBIS_invalid_stream_structure_version);
    // header flag
    f->page_flag = get8(f);
    // absolute granule position
    loc0 = get32(f);
    loc1 = get32(f);
    // @TODO: validate loc0,loc1 as valid positions?
    // stream serial number -- vorbis doesn't interleave, so discard
    get32(f);
    //if (f->serial != get32(f)) return error(f, VORBIS_incorrect_stream_serial_number);
    // page sequence number
    n = get32(f);
    f->last_page = n;
    // CRC32
    get32(f);
    // page_segments
    f->segment_count = get8(f);
    if (!getn(f, f->segments, f->segment_count))
        return error(f, VORBIS_unexpected_eof);
    // assume we _don't_ know any the sample position of any segments
    f->end_seg_with_known_loc = -2;
    if (loc0 != ~0U || loc1 != ~0U) {
        int i;
        // determine which packet is the last one that will complete
        for (i = f->segment_count - 1; i >= 0; --i)
            if (f->segments[i] < 255)
                break;
        // 'i' is now the index of the _last_ segment of a packet that ends
        if (i >= 0) {
            f->end_seg_with_known_loc = i;
            f->known_loc_for_packet = loc0;
        }
    }
    if (f->first_decode) {
        int i, len;
        ProbedPage p;
        len = 0;
        for (i = 0; i < f->segment_count; ++i)
            len += f->segments[i];
        len += 27 + f->segment_count;
        p.page_start = f->first_audio_page_offset;
        p.page_end = p.page_start + len;
        p.last_decoded_sample = loc0;
        f->p_first = p;
    }
    f->next_seg = 0;
    return TRUE;
}

static int start_page(vorb *f)
{
    if (!capture_pattern(f)) return error(f, VORBIS_missing_capture_pattern);
    return start_page_no_capturepattern(f);
}

static int start_packet(vorb *f)
{
    while (f->next_seg == -1) {
        if (!start_page(f)) return FALSE;
        if (f->page_flag & PAGEFLAG_continued_packet)
            return error(f, VORBIS_continued_packet_flag_invalid);
    }
    f->last_seg = FALSE;
    f->valid_bits = 0;
    f->packet_bytes = 0;
    f->bytes_in_seg = 0;
    // f->next_seg is now valid
    return TRUE;
}

static int maybe_start_packet(vorb *f)
{
    if (f->next_seg == -1) {
        int x = get8(f);
        if (f->eof) return FALSE; // EOF at page boundary is not an error!
        if (0x4f != x) return error(f, VORBIS_missing_capture_pattern);
        if (0x67 != get8(f)) return error(f, VORBIS_missing_capture_pattern);
        if (0x67 != get8(f)) return error(f, VORBIS_missing_capture_pattern);
        if (0x53 != get8(f)) return error(f, VORBIS_missing_capture_pattern);
        if (!start_page_no_capturepattern(f)) return FALSE;
        if (f->page_flag & PAGEFLAG_continued_packet) {
            // set up enough state that we can read this packet if we want,
            // e.g. during recovery
            f->last_seg = FALSE;
            f->bytes_in_seg = 0;
            return error(f, VORBIS_continued_packet_flag_invalid);
        }
    }
    return start_packet(f);
}

static int next_segment(vorb *f)
{
    int len;
    if (f->last_seg) return 0;
    if (f->next_seg == -1) {
        f->last_seg_which = f->segment_count - 1; // in case start_page fails
        if (!start_page(f)) { f->last_seg = 1; return 0; }
        if (!(f->page_flag & PAGEFLAG_continued_packet)) return error(f, VORBIS_continued_packet_flag_invalid);
    }
    len = f->segments[f->next_seg++];
    if (len < 255) {
        f->last_seg = TRUE;
        f->last_seg_which = f->next_seg - 1;
    }
    if (f->next_seg >= f->segment_count)
        f->next_seg = -1;
    assert(f->bytes_in_seg == 0);
    f->bytes_in_seg = len;
    return len;
}

#define EOP    (-1)
#define INVALID_BITS  (-1)

static int get8_packet_raw(vorb *f)
{
    if (!f->bytes_in_seg) {  // CLANG!
        if (f->last_seg) return EOP;
        else if (!next_segment(f)) return EOP;
    }
    assert(f->bytes_in_seg > 0);
    --f->bytes_in_seg;
    ++f->packet_bytes;
    return get8(f);
}

static int get8_packet(vorb *f)
{
    int x = get8_packet_raw(f);
    f->valid_bits = 0;
    return x;
}

static void flush_packet(vorb *f)
{
    while (get8_packet_raw(f) != EOP);
}

// @OPTIMIZE: this is the secondary bit decoder, so it's probably not as important
// as the huffman decoder?
static uint32 get_bits(vorb *f, int n)
{
    uint32 z;

    if (f->valid_bits < 0) return 0;
    if (f->valid_bits < n) {
        if (n > 24) {
            // the accumulator technique below would not work correctly in this case
            z = get_bits(f, 24);
            z += get_bits(f, n - 24) << 24;
            return z;
        }
        if (f->valid_bits == 0) f->acc = 0;
        while (f->valid_bits < n) {
            int z = get8_packet_raw(f);
            if (z == EOP) {
                f->valid_bits = INVALID_BITS;
                return 0;
            }
            f->acc += z << f->valid_bits;
            f->valid_bits += 8;
        }
    }
    if (f->valid_bits < 0) return 0;
    z = f->acc & ((1 << n) - 1);
    f->acc >>= n;
    f->valid_bits -= n;
    return z;
}

// @OPTIMIZE: primary accumulator for huffman
// expand the buffer to as many bits as possible without reading off end of packet
// it might be nice to allow f->valid_bits and f->acc to be stored in registers,
// e.g. cache them locally and decode locally
static __forceinline void prep_huffman(vorb *f)
{
    if (f->valid_bits <= 24) {
        if (f->valid_bits == 0) f->acc = 0;
        do {
            int z;
            if (f->last_seg && !f->bytes_in_seg) return;
            z = get8_packet_raw(f);
            if (z == EOP) return;
            f->acc += (unsigned)z << f->valid_bits;
            f->valid_bits += 8;
        } while (f->valid_bits <= 24);
    }
}

enum
{
    VORBIS_packet_id = 1,
    VORBIS_packet_comment = 3,
    VORBIS_packet_setup = 5
};

static int codebook_decode_scalar_raw(vorb *f, Codebook *c)
{
    int i;
    prep_huffman(f);

    if (c->codewords == NULL && c->sorted_codewords == NULL)
        return -1;

    // cases to use binary search: sorted_codewords && !c->codewords
    //                             sorted_codewords && c->entries > 8
    if (c->entries > 8 ? c->sorted_codewords != NULL : !c->codewords) {
        // binary search
        uint32 code = bit_reverse(f->acc);
        int x = 0, n = c->sorted_entries, len;

        while (n > 1) {
            // invariant: sc[x] <= code < sc[x+n]
            int m = x + (n >> 1);
            if (c->sorted_codewords[m] <= code) {
                x = m;
                n -= (n >> 1);
            }
            else {
                n >>= 1;
            }
        }
        // x is now the sorted index
        if (!c->sparse) x = c->sorted_values[x];
        // x is now sorted index if sparse, or symbol otherwise
        len = c->codeword_lengths[x];
        if (f->valid_bits >= len) {
            f->acc >>= len;
            f->valid_bits -= len;
            return x;
        }

        f->valid_bits = 0;
        return -1;
    }

    // if small, linear search
    assert(!c->sparse);
    for (i = 0; i < c->entries; ++i) {
        if (c->codeword_lengths[i] == NO_CODE) continue;
        if (c->codewords[i] == (f->acc & ((1 << c->codeword_lengths[i]) - 1))) {
            if (f->valid_bits >= c->codeword_lengths[i]) {
                f->acc >>= c->codeword_lengths[i];
                f->valid_bits -= c->codeword_lengths[i];
                return i;
            }
            f->valid_bits = 0;
            return -1;
        }
    }

    error(f, VORBIS_invalid_stream);
    f->valid_bits = 0;
    return -1;
}

#ifndef STB_VORBIS_NO_INLINE_DECODE

#define DECODE_RAW(var, f,c)                                  \
   if (f->valid_bits < STB_VORBIS_FAST_HUFFMAN_LENGTH)        \
      prep_huffman(f);                                        \
   var = f->acc & FAST_HUFFMAN_TABLE_MASK;                    \
   var = c->fast_huffman[var];                                \
   if (var >= 0) {                                            \
      int n = c->codeword_lengths[var];                       \
      f->acc >>= n;                                           \
      f->valid_bits -= n;                                     \
      if (f->valid_bits < 0) { f->valid_bits = 0; var = -1; } \
   } else {                                                   \
      var = codebook_decode_scalar_raw(f,c);                  \
   }

#else

static int codebook_decode_scalar(vorb *f, Codebook *c)
{
    int i;
    if (f->valid_bits < STB_VORBIS_FAST_HUFFMAN_LENGTH)
        prep_huffman(f);
    // fast huffman table lookup
    i = f->acc & FAST_HUFFMAN_TABLE_MASK;
    i = c->fast_huffman[i];
    if (i >= 0) {
        f->acc >>= c->codeword_lengths[i];
        f->valid_bits -= c->codeword_lengths[i];
        if (f->valid_bits < 0) { f->valid_bits = 0; return -1; }
        return i;
    }
    return codebook_decode_scalar_raw(f, c);
}

#define DECODE_RAW(var,f,c)    var = codebook_decode_scalar(f,c);

#endif

#define DECODE(var,f,c)                                       \
   DECODE_RAW(var,f,c)                                        \
   if (c->sparse) var = c->sorted_values[var];

#ifndef STB_VORBIS_DIVIDES_IN_CODEBOOK
#define DECODE_VQ(var,f,c)   DECODE_RAW(var,f,c)
#else
#define DECODE_VQ(var,f,c)   DECODE(var,f,c)
#endif






// CODEBOOK_ELEMENT_FAST is an optimization for the CODEBOOK_FLOATS case
// where we avoid one addition
#define CODEBOOK_ELEMENT(c,off)          (c->multiplicands[off])
#define CODEBOOK_ELEMENT_FAST(c,off)     (c->multiplicands[off])
#define CODEBOOK_ELEMENT_BASE(c)         (0)

static int codebook_decode_start(vorb *f, Codebook *c)
{
    int z = -1;

    // type 0 is only legal in a scalar context
    if (c->lookup_type == 0)
        error(f, VORBIS_invalid_stream);
    else {
        DECODE_VQ(z, f, c);
        if (c->sparse) assert(z < c->sorted_entries);
        if (z < 0) {  // check for EOP
            if (!f->bytes_in_seg)
                if (f->last_seg)
                    return z;
            error(f, VORBIS_invalid_stream);
        }
    }
    return z;
}

static int codebook_decode(vorb *f, Codebook *c, float *output, int len)
{
    int i, z = codebook_decode_start(f, c);
    if (z < 0) return FALSE;
    if (len > c->dimensions) len = c->dimensions;

#ifdef STB_VORBIS_DIVIDES_IN_CODEBOOK
    if (c->lookup_type == 1) {
        float last = CODEBOOK_ELEMENT_BASE(c);
        int div = 1;
        for (i = 0; i < len; ++i) {
            int off = (z / div) % c->lookup_values;
            float val = CODEBOOK_ELEMENT_FAST(c, off) + last;
            output[i] += val;
            if (c->sequence_p) last = val + c->minimum_value;
            div *= c->lookup_values;
        }
        return TRUE;
    }
#endif

    z *= c->dimensions;
    if (c->sequence_p) {
        float last = CODEBOOK_ELEMENT_BASE(c);
        for (i = 0; i < len; ++i) {
            float val = CODEBOOK_ELEMENT_FAST(c, z + i) + last;
            output[i] += val;
            last = val + c->minimum_value;
        }
    }
    else {
        float last = CODEBOOK_ELEMENT_BASE(c);
        for (i = 0; i < len; ++i) {
            output[i] += CODEBOOK_ELEMENT_FAST(c, z + i) + last;
        }
    }

    return TRUE;
}

static int codebook_decode_step(vorb *f, Codebook *c, float *output, int len, int step)
{
    int i, z = codebook_decode_start(f, c);
    float last = CODEBOOK_ELEMENT_BASE(c);
    if (z < 0) return FALSE;
    if (len > c->dimensions) len = c->dimensions;

#ifdef STB_VORBIS_DIVIDES_IN_CODEBOOK
    if (c->lookup_type == 1) {
        int div = 1;
        for (i = 0; i < len; ++i) {
            int off = (z / div) % c->lookup_values;
            float val = CODEBOOK_ELEMENT_FAST(c, off) + last;
            output[i*step] += val;
            if (c->sequence_p) last = val;
            div *= c->lookup_values;
        }
        return TRUE;
    }
#endif

    z *= c->dimensions;
    for (i = 0; i < len; ++i) {
        float val = CODEBOOK_ELEMENT_FAST(c, z + i) + last;
        output[i*step] += val;
        if (c->sequence_p) last = val;
    }

    return TRUE;
}

static int codebook_decode_deinterleave_repeat(vorb *f, Codebook *c, float **outputs, int ch, int *c_inter_p, int *p_inter_p, int len, int total_decode)
{
    int c_inter = *c_inter_p;
    int p_inter = *p_inter_p;
    int i, z, effective = c->dimensions;

    // type 0 is only legal in a scalar context
    if (c->lookup_type == 0)   return error(f, VORBIS_invalid_stream);

    while (total_decode > 0) {
        float last = CODEBOOK_ELEMENT_BASE(c);
        DECODE_VQ(z, f, c);
#ifndef STB_VORBIS_DIVIDES_IN_CODEBOOK
        assert(!c->sparse || z < c->sorted_entries);
#endif
        if (z < 0) {
            if (!f->bytes_in_seg)
                if (f->last_seg) return FALSE;
            return error(f, VORBIS_invalid_stream);
        }

        // if this will take us off the end of the buffers, stop short!
        // we check by computing the length of the virtual interleaved
        // buffer (len*ch), our current offset within it (p_inter*ch)+(c_inter),
        // and the length we'll be using (effective)
        if (c_inter + p_inter*ch + effective > len * ch) {
            effective = len*ch - (p_inter*ch - c_inter);
        }

#ifdef STB_VORBIS_DIVIDES_IN_CODEBOOK
        if (c->lookup_type == 1) {
            int div = 1;
            for (i = 0; i < effective; ++i) {
                int off = (z / div) % c->lookup_values;
                float val = CODEBOOK_ELEMENT_FAST(c, off) + last;
                if (outputs[c_inter])
                    outputs[c_inter][p_inter] += val;
                if (++c_inter == ch) { c_inter = 0; ++p_inter; }
                if (c->sequence_p) last = val;
                div *= c->lookup_values;
            }
        }
        else
#endif
        {
            z *= c->dimensions;
            if (c->sequence_p) {
                for (i = 0; i < effective; ++i) {
                    float val = CODEBOOK_ELEMENT_FAST(c, z + i) + last;
                    if (outputs[c_inter])
                        outputs[c_inter][p_inter] += val;
                    if (++c_inter == ch) { c_inter = 0; ++p_inter; }
                    last = val;
                }
            }
            else {
                for (i = 0; i < effective; ++i) {
                    float val = CODEBOOK_ELEMENT_FAST(c, z + i) + last;
                    if (outputs[c_inter])
                        outputs[c_inter][p_inter] += val;
                    if (++c_inter == ch) { c_inter = 0; ++p_inter; }
                }
            }
        }

        total_decode -= effective;
    }
    *c_inter_p = c_inter;
    *p_inter_p = p_inter;
    return TRUE;
}

#ifndef STB_VORBIS_DIVIDES_IN_CODEBOOK
static int codebook_decode_deinterleave_repeat_2(vorb *f, Codebook *c, float **outputs, int *c_inter_p, int *p_inter_p, int len, int total_decode)
{
    int c_inter = *c_inter_p;
    int p_inter = *p_inter_p;
    int i, z, effective = c->dimensions;

    // type 0 is only legal in a scalar context
    if (c->lookup_type == 0)   return error(f, VORBIS_invalid_stream);

    while (total_decode > 0) {
        float last = CODEBOOK_ELEMENT_BASE(c);
        DECODE_VQ(z, f, c);

        if (z < 0) {
            if (!f->bytes_in_seg)
                if (f->last_seg) return FALSE;
            return error(f, VORBIS_invalid_stream);
        }

        // if this will take us off the end of the buffers, stop short!
        // we check by computing the length of the virtual interleaved
        // buffer (len*ch), our current offset within it (p_inter*ch)+(c_inter),
        // and the length we'll be using (effective)
        if (c_inter + p_inter * 2 + effective > len * 2) {
            effective = len * 2 - (p_inter * 2 - c_inter);
        }

        {
            z *= c->dimensions;
            if (c->sequence_p) {
                // haven't optimized this case because I don't have any examples
                for (i = 0; i < effective; ++i) {
                    float val = CODEBOOK_ELEMENT_FAST(c, z + i) + last;
                    if (outputs[c_inter])
                        outputs[c_inter][p_inter] += val;
                    if (++c_inter == 2) { c_inter = 0; ++p_inter; }
                    last = val;
                }
            }
            else {
                i = 0;
                if (c_inter == 1 && i < effective) {
                    float val = CODEBOOK_ELEMENT_FAST(c, z + i) + last;
                    if (outputs[c_inter])
                        outputs[c_inter][p_inter] += val;
                    c_inter = 0; ++p_inter;
                    ++i;
                }
                {
                    float *z0 = outputs[0];
                    float *z1 = outputs[1];
                    for (; i + 1 < effective;) {
                        float v0 = CODEBOOK_ELEMENT_FAST(c, z + i) + last;
                        float v1 = CODEBOOK_ELEMENT_FAST(c, z + i + 1) + last;
                        if (z0)
                            z0[p_inter] += v0;
                        if (z1)
                            z1[p_inter] += v1;
                        ++p_inter;
                        i += 2;
                    }
                }
                if (i < effective) {
                    float val = CODEBOOK_ELEMENT_FAST(c, z + i) + last;
                    if (outputs[c_inter])
                        outputs[c_inter][p_inter] += val;
                    if (++c_inter == 2) { c_inter = 0; ++p_inter; }
                }
            }
        }

        total_decode -= effective;
    }
    *c_inter_p = c_inter;
    *p_inter_p = p_inter;
    return TRUE;
}
#endif

static int predict_point(int x, int x0, int x1, int y0, int y1)
{
    int dy = y1 - y0;
    int adx = x1 - x0;
    // @OPTIMIZE: force int division to round in the right direction... is this necessary on x86?
    int err = abs(dy) * (x - x0);
    int off = err / adx;
    return dy < 0 ? y0 - off : y0 + off;
}

// the following table is block-copied from the specification
static float inverse_db_table[256] =
{
    1.0649863e-07f, 1.1341951e-07f, 1.2079015e-07f, 1.2863978e-07f,
    1.3699951e-07f, 1.4590251e-07f, 1.5538408e-07f, 1.6548181e-07f,
    1.7623575e-07f, 1.8768855e-07f, 1.9988561e-07f, 2.1287530e-07f,
    2.2670913e-07f, 2.4144197e-07f, 2.5713223e-07f, 2.7384213e-07f,
    2.9163793e-07f, 3.1059021e-07f, 3.3077411e-07f, 3.5226968e-07f,
    3.7516214e-07f, 3.9954229e-07f, 4.2550680e-07f, 4.5315863e-07f,
    4.8260743e-07f, 5.1396998e-07f, 5.4737065e-07f, 5.8294187e-07f,
    6.2082472e-07f, 6.6116941e-07f, 7.0413592e-07f, 7.4989464e-07f,
    7.9862701e-07f, 8.5052630e-07f, 9.0579828e-07f, 9.6466216e-07f,
    1.0273513e-06f, 1.0941144e-06f, 1.1652161e-06f, 1.2409384e-06f,
    1.3215816e-06f, 1.4074654e-06f, 1.4989305e-06f, 1.5963394e-06f,
    1.7000785e-06f, 1.8105592e-06f, 1.9282195e-06f, 2.0535261e-06f,
    2.1869758e-06f, 2.3290978e-06f, 2.4804557e-06f, 2.6416497e-06f,
    2.8133190e-06f, 2.9961443e-06f, 3.1908506e-06f, 3.3982101e-06f,
    3.6190449e-06f, 3.8542308e-06f, 4.1047004e-06f, 4.3714470e-06f,
    4.6555282e-06f, 4.9580707e-06f, 5.2802740e-06f, 5.6234160e-06f,
    5.9888572e-06f, 6.3780469e-06f, 6.7925283e-06f, 7.2339451e-06f,
    7.7040476e-06f, 8.2047000e-06f, 8.7378876e-06f, 9.3057248e-06f,
    9.9104632e-06f, 1.0554501e-05f, 1.1240392e-05f, 1.1970856e-05f,
    1.2748789e-05f, 1.3577278e-05f, 1.4459606e-05f, 1.5399272e-05f,
    1.6400004e-05f, 1.7465768e-05f, 1.8600792e-05f, 1.9809576e-05f,
    2.1096914e-05f, 2.2467911e-05f, 2.3928002e-05f, 2.5482978e-05f,
    2.7139006e-05f, 2.8902651e-05f, 3.0780908e-05f, 3.2781225e-05f,
    3.4911534e-05f, 3.7180282e-05f, 3.9596466e-05f, 4.2169667e-05f,
    4.4910090e-05f, 4.7828601e-05f, 5.0936773e-05f, 5.4246931e-05f,
    5.7772202e-05f, 6.1526565e-05f, 6.5524908e-05f, 6.9783085e-05f,
    7.4317983e-05f, 7.9147585e-05f, 8.4291040e-05f, 8.9768747e-05f,
    9.5602426e-05f, 0.00010181521f, 0.00010843174f, 0.00011547824f,
    0.00012298267f, 0.00013097477f, 0.00013948625f, 0.00014855085f,
    0.00015820453f, 0.00016848555f, 0.00017943469f, 0.00019109536f,
    0.00020351382f, 0.00021673929f, 0.00023082423f, 0.00024582449f,
    0.00026179955f, 0.00027881276f, 0.00029693158f, 0.00031622787f,
    0.00033677814f, 0.00035866388f, 0.00038197188f, 0.00040679456f,
    0.00043323036f, 0.00046138411f, 0.00049136745f, 0.00052329927f,
    0.00055730621f, 0.00059352311f, 0.00063209358f, 0.00067317058f,
    0.00071691700f, 0.00076350630f, 0.00081312324f, 0.00086596457f,
    0.00092223983f, 0.00098217216f, 0.0010459992f,  0.0011139742f,
    0.0011863665f,  0.0012634633f,  0.0013455702f,  0.0014330129f,
    0.0015261382f,  0.0016253153f,  0.0017309374f,  0.0018434235f,
    0.0019632195f,  0.0020908006f,  0.0022266726f,  0.0023713743f,
    0.0025254795f,  0.0026895994f,  0.0028643847f,  0.0030505286f,
    0.0032487691f,  0.0034598925f,  0.0036847358f,  0.0039241906f,
    0.0041792066f,  0.0044507950f,  0.0047400328f,  0.0050480668f,
    0.0053761186f,  0.0057254891f,  0.0060975636f,  0.0064938176f,
    0.0069158225f,  0.0073652516f,  0.0078438871f,  0.0083536271f,
    0.0088964928f,  0.009474637f,   0.010090352f,   0.010746080f,
    0.011444421f,   0.012188144f,   0.012980198f,   0.013823725f,
    0.014722068f,   0.015678791f,   0.016697687f,   0.017782797f,
    0.018938423f,   0.020169149f,   0.021479854f,   0.022875735f,
    0.024362330f,   0.025945531f,   0.027631618f,   0.029427276f,
    0.031339626f,   0.033376252f,   0.035545228f,   0.037855157f,
    0.040315199f,   0.042935108f,   0.045725273f,   0.048696758f,
    0.051861348f,   0.055231591f,   0.058820850f,   0.062643361f,
    0.066714279f,   0.071049749f,   0.075666962f,   0.080584227f,
    0.085821044f,   0.091398179f,   0.097337747f,   0.10366330f,
    0.11039993f,    0.11757434f,    0.12521498f,    0.13335215f,
    0.14201813f,    0.15124727f,    0.16107617f,    0.17154380f,
    0.18269168f,    0.19456402f,    0.20720788f,    0.22067342f,
    0.23501402f,    0.25028656f,    0.26655159f,    0.28387361f,
    0.30232132f,    0.32196786f,    0.34289114f,    0.36517414f,
    0.38890521f,    0.41417847f,    0.44109412f,    0.46975890f,
    0.50028648f,    0.53279791f,    0.56742212f,    0.60429640f,
    0.64356699f,    0.68538959f,    0.72993007f,    0.77736504f,
    0.82788260f,    0.88168307f,    0.9389798f,     1.0f
};


// @OPTIMIZE: if you want to replace this bresenham line-drawing routine,
// note that you must produce bit-identical output to decode correctly;
// this specific sequence of operations is specified in the spec (it's
// drawing integer-quantized frequency-space lines that the encoder
// expects to be exactly the same)
//     ... also, isn't the whole point of Bresenham's algorithm to NOT
// have to divide in the setup? sigh.
#ifndef STB_VORBIS_NO_DEFER_FLOOR
#define LINE_OP(a,b)   a *= b
#else
#define LINE_OP(a,b)   a = b
#endif

#ifdef STB_VORBIS_DIVIDE_TABLE
#define DIVTAB_NUMER   32
#define DIVTAB_DENOM   64
int8 integer_divide_table[DIVTAB_NUMER][DIVTAB_DENOM]; // 2KB
#endif

static __forceinline void draw_line(float *output, int x0, int y0, int x1, int y1, int n)
{
    int dy = y1 - y0;
    int adx = x1 - x0;
    int ady = abs(dy);
    int base;
    int x = x0, y = y0;
    int err = 0;
    int sy;

#ifdef STB_VORBIS_DIVIDE_TABLE
    if (adx < DIVTAB_DENOM && ady < DIVTAB_NUMER) {
        if (dy < 0) {
            base = -integer_divide_table[ady][adx];
            sy = base - 1;
        }
        else {
            base = integer_divide_table[ady][adx];
            sy = base + 1;
        }
    }
    else {
        base = dy / adx;
        if (dy < 0)
            sy = base - 1;
        else
            sy = base + 1;
    }
#else
    base = dy / adx;
    if (dy < 0)
        sy = base - 1;
    else
        sy = base + 1;
#endif
    ady -= abs(base) * adx;
    if (x1 > n) x1 = n;
    if (x < x1) {
        LINE_OP(output[x], inverse_db_table[y]);
        for (++x; x < x1; ++x) {
            err += ady;
            if (err >= adx) {
                err -= adx;
                y += sy;
            }
            else
                y += base;
            LINE_OP(output[x], inverse_db_table[y]);
        }
    }
}

static int residue_decode(vorb *f, Codebook *book, float *target, int offset, int n, int rtype)
{
    int k;
    if (rtype == 0) {
        int step = n / book->dimensions;
        for (k = 0; k < step; ++k)
            if (!codebook_decode_step(f, book, target + offset + k, n - offset - k, step))
                return FALSE;
    }
    else {
        for (k = 0; k < n; ) {
            if (!codebook_decode(f, book, target + offset, n - k))
                return FALSE;
            k += book->dimensions;
            offset += book->dimensions;
        }
    }
    return TRUE;
}

static void decode_residue(vorb *f, float *residue_buffers[], int ch, int n, int rn, uint8 *do_not_decode)
{
    int i, j, pass;
    Residue *r = f->residue_config + rn;
    int rtype = f->residue_types[rn];
    int c = r->classbook;
    int classwords = f->codebooks[c].dimensions;
    int n_read = r->end - r->begin;
    int part_read = n_read / r->part_size;
    int temp_alloc_point = temp_alloc_save(f);
#ifndef STB_VORBIS_DIVIDES_IN_RESIDUE
    uint8 ***part_classdata = (uint8 ***)temp_block_array(f, f->channels, part_read * sizeof(**part_classdata));
#else
    int **classifications = (int **)temp_block_array(f, f->channels, part_read * sizeof(**classifications));
#endif

    CHECK(f);

    for (i = 0; i < ch; ++i)
        if (!do_not_decode[i])
            memset(residue_buffers[i], 0, sizeof(float) * n);

    if (rtype == 2 && ch != 1) {
        for (j = 0; j < ch; ++j)
            if (!do_not_decode[j])
                break;
        if (j == ch)
            goto done;

        for (pass = 0; pass < 8; ++pass) {
            int pcount = 0, class_set = 0;
            if (ch == 2) {
                while (pcount < part_read) {
                    int z = r->begin + pcount*r->part_size;
                    int c_inter = (z & 1), p_inter = z >> 1;
                    if (pass == 0) {
                        Codebook *c = f->codebooks + r->classbook;
                        int q;
                        DECODE(q, f, c);
                        if (q == EOP) goto done;
#ifndef STB_VORBIS_DIVIDES_IN_RESIDUE
                        part_classdata[0][class_set] = r->classdata[q];
#else
                        for (i = classwords - 1; i >= 0; --i) {
                            classifications[0][i + pcount] = q % r->classifications;
                            q /= r->classifications;
                        }
#endif
                    }
                    for (i = 0; i < classwords && pcount < part_read; ++i, ++pcount) {
                        int z = r->begin + pcount*r->part_size;
#ifndef STB_VORBIS_DIVIDES_IN_RESIDUE
                        int c = part_classdata[0][class_set][i];
#else
                        int c = classifications[0][pcount];
#endif
                        int b = r->residue_books[c][pass];
                        if (b >= 0) {
                            Codebook *book = f->codebooks + b;
#ifdef STB_VORBIS_DIVIDES_IN_CODEBOOK
                            if (!codebook_decode_deinterleave_repeat(f, book, residue_buffers, ch, &c_inter, &p_inter, n, r->part_size))
                                goto done;
#else
                            // saves 1%
                            if (!codebook_decode_deinterleave_repeat(f, book, residue_buffers, ch, &c_inter, &p_inter, n, r->part_size))
                                goto done;
#endif
                        }
                        else {
                            z += r->part_size;
                            c_inter = z & 1;
                            p_inter = z >> 1;
                        }
                    }
#ifndef STB_VORBIS_DIVIDES_IN_RESIDUE
                    ++class_set;
#endif
                }
            }
            else if (ch == 1) {
                while (pcount < part_read) {
                    int z = r->begin + pcount*r->part_size;
                    int c_inter = 0, p_inter = z;
                    if (pass == 0) {
                        Codebook *c = f->codebooks + r->classbook;
                        int q;
                        DECODE(q, f, c);
                        if (q == EOP) goto done;
#ifndef STB_VORBIS_DIVIDES_IN_RESIDUE
                        part_classdata[0][class_set] = r->classdata[q];
#else
                        for (i = classwords - 1; i >= 0; --i) {
                            classifications[0][i + pcount] = q % r->classifications;
                            q /= r->classifications;
                        }
#endif
                    }
                    for (i = 0; i < classwords && pcount < part_read; ++i, ++pcount) {
                        int z = r->begin + pcount*r->part_size;
#ifndef STB_VORBIS_DIVIDES_IN_RESIDUE
                        int c = part_classdata[0][class_set][i];
#else
                        int c = classifications[0][pcount];
#endif
                        int b = r->residue_books[c][pass];
                        if (b >= 0) {
                            Codebook *book = f->codebooks + b;
                            if (!codebook_decode_deinterleave_repeat(f, book, residue_buffers, ch, &c_inter, &p_inter, n, r->part_size))
                                goto done;
                        }
                        else {
                            z += r->part_size;
                            c_inter = 0;
                            p_inter = z;
                        }
                    }
#ifndef STB_VORBIS_DIVIDES_IN_RESIDUE
                    ++class_set;
#endif
                }
            }
            else {
                while (pcount < part_read) {
                    int z = r->begin + pcount*r->part_size;
                    int c_inter = z % ch, p_inter = z / ch;
                    if (pass == 0) {
                        Codebook *c = f->codebooks + r->classbook;
                        int q;
                        DECODE(q, f, c);
                        if (q == EOP) goto done;
#ifndef STB_VORBIS_DIVIDES_IN_RESIDUE
                        part_classdata[0][class_set] = r->classdata[q];
#else
                        for (i = classwords - 1; i >= 0; --i) {
                            classifications[0][i + pcount] = q % r->classifications;
                            q /= r->classifications;
                        }
#endif
                    }
                    for (i = 0; i < classwords && pcount < part_read; ++i, ++pcount) {
                        int z = r->begin + pcount*r->part_size;
#ifndef STB_VORBIS_DIVIDES_IN_RESIDUE
                        int c = part_classdata[0][class_set][i];
#else
                        int c = classifications[0][pcount];
#endif
                        int b = r->residue_books[c][pass];
                        if (b >= 0) {
                            Codebook *book = f->codebooks + b;
                            if (!codebook_decode_deinterleave_repeat(f, book, residue_buffers, ch, &c_inter, &p_inter, n, r->part_size))
                                goto done;
                        }
                        else {
                            z += r->part_size;
                            c_inter = z % ch;
                            p_inter = z / ch;
                        }
                    }
#ifndef STB_VORBIS_DIVIDES_IN_RESIDUE
                    ++class_set;
#endif
                }
            }
        }
        goto done;
    }
    CHECK(f);

    for (pass = 0; pass < 8; ++pass) {
        int pcount = 0, class_set = 0;
        while (pcount < part_read) {
            if (pass == 0) {
                for (j = 0; j < ch; ++j) {
                    if (!do_not_decode[j]) {
                        Codebook *c = f->codebooks + r->classbook;
                        int temp;
                        DECODE(temp, f, c);
                        if (temp == EOP) goto done;
#ifndef STB_VORBIS_DIVIDES_IN_RESIDUE
                        part_classdata[j][class_set] = r->classdata[temp];
#else
                        for (i = classwords - 1; i >= 0; --i) {
                            classifications[j][i + pcount] = temp % r->classifications;
                            temp /= r->classifications;
                        }
#endif
                    }
                }
            }
            for (i = 0; i < classwords && pcount < part_read; ++i, ++pcount) {
                for (j = 0; j < ch; ++j) {
                    if (!do_not_decode[j]) {
#ifndef STB_VORBIS_DIVIDES_IN_RESIDUE
                        int c = part_classdata[j][class_set][i];
#else
                        int c = classifications[j][pcount];
#endif
                        int b = r->residue_books[c][pass];
                        if (b >= 0) {
                            float *target = residue_buffers[j];
                            int offset = r->begin + pcount * r->part_size;
                            int n = r->part_size;
                            Codebook *book = f->codebooks + b;
                            if (!residue_decode(f, book, target, offset, n, rtype))
                                goto done;
                        }
                    }
                }
            }
#ifndef STB_VORBIS_DIVIDES_IN_RESIDUE
            ++class_set;
#endif
        }
    }
done:
    CHECK(f);
    temp_alloc_restore(f, temp_alloc_point);
}


#if 0
// slow way for debugging
void inverse_mdct_slow(float *buffer, int n)
{
    int i, j;
    int n2 = n >> 1;
    float *x = (float *)malloc(sizeof(*x) * n2);
    memcpy(x, buffer, sizeof(*x) * n2);
    for (i = 0; i < n; ++i) {
        float acc = 0;
        for (j = 0; j < n2; ++j)
            // formula from paper:
            //acc += n/4.0f * x[j] * (float) cos(M_PI / 2 / n * (2 * i + 1 + n/2.0)*(2*j+1));
            // formula from wikipedia
            //acc += 2.0f / n2 * x[j] * (float) cos(M_PI/n2 * (i + 0.5 + n2/2)*(j + 0.5));
            // these are equivalent, except the formula from the paper inverts the multiplier!
            // however, what actually works is NO MULTIPLIER!?!
            //acc += 64 * 2.0f / n2 * x[j] * (float) cos(M_PI/n2 * (i + 0.5 + n2/2)*(j + 0.5));
            acc += x[j] * (float)cos(M_PI / 2 / n * (2 * i + 1 + n / 2.0)*(2 * j + 1));
        buffer[i] = acc;
    }
    free(x);
}
#elif 0
// same as above, but just barely able to run in real time on modern machines
void inverse_mdct_slow(float *buffer, int n, vorb *f, int blocktype)
{
    float mcos[16384];
    int i, j;
    int n2 = n >> 1, nmask = (n << 2) - 1;
    float *x = (float *)malloc(sizeof(*x) * n2);
    memcpy(x, buffer, sizeof(*x) * n2);
    for (i = 0; i < 4 * n; ++i)
        mcos[i] = (float)cos(M_PI / 2 * i / n);

    for (i = 0; i < n; ++i) {
        float acc = 0;
        for (j = 0; j < n2; ++j)
            acc += x[j] * mcos[(2 * i + 1 + n2)*(2 * j + 1) & nmask];
        buffer[i] = acc;
    }
    free(x);
}
#elif 0
// transform to use a slow dct-iv; this is STILL basically trivial,
// but only requires half as many ops
void dct_iv_slow(float *buffer, int n)
{
    float mcos[16384];
    float x[2048];
    int i, j;
    int n2 = n >> 1, nmask = (n << 3) - 1;
    memcpy(x, buffer, sizeof(*x) * n);
    for (i = 0; i < 8 * n; ++i)
        mcos[i] = (float)cos(M_PI / 4 * i / n);
    for (i = 0; i < n; ++i) {
        float acc = 0;
        for (j = 0; j < n; ++j)
            acc += x[j] * mcos[((2 * i + 1)*(2 * j + 1)) & nmask];
        buffer[i] = acc;
    }
}

void inverse_mdct_slow(float *buffer, int n, vorb *f, int blocktype)
{
    int i, n4 = n >> 2, n2 = n >> 1, n3_4 = n - n4;
    float temp[4096];

    memcpy(temp, buffer, n2 * sizeof(float));
    dct_iv_slow(temp, n2);  // returns -c'-d, a-b'

    for (i = 0; i < n4; ++i) buffer[i] = temp[i + n4];            // a-b'
    for (; i < n3_4; ++i) buffer[i] = -temp[n3_4 - i - 1];   // b-a', c+d'
    for (; i < n; ++i) buffer[i] = -temp[i - n3_4];       // c'+d
}
#endif

#ifndef LIBVORBIS_MDCT
#define LIBVORBIS_MDCT 0
#endif

#if LIBVORBIS_MDCT
// directly call the vorbis MDCT using an interface documented
// by Jeff Roberts... useful for performance comparison
typedef struct
{
    int n;
    int log2n;

    float *trig;
    int   *bitrev;

    float scale;
} mdct_lookup;

extern void mdct_init(mdct_lookup *lookup, int n);
extern void mdct_clear(mdct_lookup *l);
extern void mdct_backward(mdct_lookup *init, float *in, float *out);

mdct_lookup M1, M2;

void inverse_mdct(float *buffer, int n, vorb *f, int blocktype)
{
    mdct_lookup *M;
    if (M1.n == n) M = &M1;
    else if (M2.n == n) M = &M2;
    else if (M1.n == 0) { mdct_init(&M1, n); M = &M1; }
    else {
        if (M2.n) __asm int 3;
        mdct_init(&M2, n);
        M = &M2;
    }

    mdct_backward(M, buffer, buffer);
}
#endif


// the following were split out into separate functions while optimizing;
// they could be pushed back up but eh. __forceinline showed no change;
// they're probably already being inlined.
static void imdct_step3_iter0_loop(int n, float *e, int i_off, int k_off, float *A)
{
    float *ee0 = e + i_off;
    float *ee2 = ee0 + k_off;
    int i;

    assert((n & 3) == 0);
    for (i = (n >> 2); i > 0; --i) {
        float k00_20, k01_21;
        k00_20 = ee0[0] - ee2[0];
        k01_21 = ee0[-1] - ee2[-1];
        ee0[0] += ee2[0];//ee0[ 0] = ee0[ 0] + ee2[ 0];
        ee0[-1] += ee2[-1];//ee0[-1] = ee0[-1] + ee2[-1];
        ee2[0] = k00_20 * A[0] - k01_21 * A[1];
        ee2[-1] = k01_21 * A[0] + k00_20 * A[1];
        A += 8;

        k00_20 = ee0[-2] - ee2[-2];
        k01_21 = ee0[-3] - ee2[-3];
        ee0[-2] += ee2[-2];//ee0[-2] = ee0[-2] + ee2[-2];
        ee0[-3] += ee2[-3];//ee0[-3] = ee0[-3] + ee2[-3];
        ee2[-2] = k00_20 * A[0] - k01_21 * A[1];
        ee2[-3] = k01_21 * A[0] + k00_20 * A[1];
        A += 8;

        k00_20 = ee0[-4] - ee2[-4];
        k01_21 = ee0[-5] - ee2[-5];
        ee0[-4] += ee2[-4];//ee0[-4] = ee0[-4] + ee2[-4];
        ee0[-5] += ee2[-5];//ee0[-5] = ee0[-5] + ee2[-5];
        ee2[-4] = k00_20 * A[0] - k01_21 * A[1];
        ee2[-5] = k01_21 * A[0] + k00_20 * A[1];
        A += 8;

        k00_20 = ee0[-6] - ee2[-6];
        k01_21 = ee0[-7] - ee2[-7];
        ee0[-6] += ee2[-6];//ee0[-6] = ee0[-6] + ee2[-6];
        ee0[-7] += ee2[-7];//ee0[-7] = ee0[-7] + ee2[-7];
        ee2[-6] = k00_20 * A[0] - k01_21 * A[1];
        ee2[-7] = k01_21 * A[0] + k00_20 * A[1];
        A += 8;
        ee0 -= 8;
        ee2 -= 8;
    }
}

static void imdct_step3_inner_r_loop(int lim, float *e, int d0, int k_off, float *A, int k1)
{
    int i;
    float k00_20, k01_21;

    float *e0 = e + d0;
    float *e2 = e0 + k_off;

    for (i = lim >> 2; i > 0; --i) {
        k00_20 = e0[-0] - e2[-0];
        k01_21 = e0[-1] - e2[-1];
        e0[-0] += e2[-0];//e0[-0] = e0[-0] + e2[-0];
        e0[-1] += e2[-1];//e0[-1] = e0[-1] + e2[-1];
        e2[-0] = (k00_20)*A[0] - (k01_21)* A[1];
        e2[-1] = (k01_21)*A[0] + (k00_20)* A[1];

        A += k1;

        k00_20 = e0[-2] - e2[-2];
        k01_21 = e0[-3] - e2[-3];
        e0[-2] += e2[-2];//e0[-2] = e0[-2] + e2[-2];
        e0[-3] += e2[-3];//e0[-3] = e0[-3] + e2[-3];
        e2[-2] = (k00_20)*A[0] - (k01_21)* A[1];
        e2[-3] = (k01_21)*A[0] + (k00_20)* A[1];

        A += k1;

        k00_20 = e0[-4] - e2[-4];
        k01_21 = e0[-5] - e2[-5];
        e0[-4] += e2[-4];//e0[-4] = e0[-4] + e2[-4];
        e0[-5] += e2[-5];//e0[-5] = e0[-5] + e2[-5];
        e2[-4] = (k00_20)*A[0] - (k01_21)* A[1];
        e2[-5] = (k01_21)*A[0] + (k00_20)* A[1];

        A += k1;

        k00_20 = e0[-6] - e2[-6];
        k01_21 = e0[-7] - e2[-7];
        e0[-6] += e2[-6];//e0[-6] = e0[-6] + e2[-6];
        e0[-7] += e2[-7];//e0[-7] = e0[-7] + e2[-7];
        e2[-6] = (k00_20)*A[0] - (k01_21)* A[1];
        e2[-7] = (k01_21)*A[0] + (k00_20)* A[1];

        e0 -= 8;
        e2 -= 8;

        A += k1;
    }
}

static void imdct_step3_inner_s_loop(int n, float *e, int i_off, int k_off, float *A, int a_off, int k0)
{
    int i;
    float A0 = A[0];
    float A1 = A[0 + 1];
    float A2 = A[0 + a_off];
    float A3 = A[0 + a_off + 1];
    float A4 = A[0 + a_off * 2 + 0];
    float A5 = A[0 + a_off * 2 + 1];
    float A6 = A[0 + a_off * 3 + 0];
    float A7 = A[0 + a_off * 3 + 1];

    float k00, k11;

    float *ee0 = e + i_off;
    float *ee2 = ee0 + k_off;

    for (i = n; i > 0; --i) {
        k00 = ee0[0] - ee2[0];
        k11 = ee0[-1] - ee2[-1];
        ee0[0] = ee0[0] + ee2[0];
        ee0[-1] = ee0[-1] + ee2[-1];
        ee2[0] = (k00)* A0 - (k11)* A1;
        ee2[-1] = (k11)* A0 + (k00)* A1;

        k00 = ee0[-2] - ee2[-2];
        k11 = ee0[-3] - ee2[-3];
        ee0[-2] = ee0[-2] + ee2[-2];
        ee0[-3] = ee0[-3] + ee2[-3];
        ee2[-2] = (k00)* A2 - (k11)* A3;
        ee2[-3] = (k11)* A2 + (k00)* A3;

        k00 = ee0[-4] - ee2[-4];
        k11 = ee0[-5] - ee2[-5];
        ee0[-4] = ee0[-4] + ee2[-4];
        ee0[-5] = ee0[-5] + ee2[-5];
        ee2[-4] = (k00)* A4 - (k11)* A5;
        ee2[-5] = (k11)* A4 + (k00)* A5;

        k00 = ee0[-6] - ee2[-6];
        k11 = ee0[-7] - ee2[-7];
        ee0[-6] = ee0[-6] + ee2[-6];
        ee0[-7] = ee0[-7] + ee2[-7];
        ee2[-6] = (k00)* A6 - (k11)* A7;
        ee2[-7] = (k11)* A6 + (k00)* A7;

        ee0 -= k0;
        ee2 -= k0;
    }
}

static __forceinline void iter_54(float *z)
{
    float k00, k11, k22, k33;
    float y0, y1, y2, y3;

    k00 = z[0] - z[-4];
    y0 = z[0] + z[-4];
    y2 = z[-2] + z[-6];
    k22 = z[-2] - z[-6];

    z[-0] = y0 + y2;      // z0 + z4 + z2 + z6
    z[-2] = y0 - y2;      // z0 + z4 - z2 - z6

                          // done with y0,y2

    k33 = z[-3] - z[-7];

    z[-4] = k00 + k33;    // z0 - z4 + z3 - z7
    z[-6] = k00 - k33;    // z0 - z4 - z3 + z7

                          // done with k33

    k11 = z[-1] - z[-5];
    y1 = z[-1] + z[-5];
    y3 = z[-3] + z[-7];

    z[-1] = y1 + y3;      // z1 + z5 + z3 + z7
    z[-3] = y1 - y3;      // z1 + z5 - z3 - z7
    z[-5] = k11 - k22;    // z1 - z5 + z2 - z6
    z[-7] = k11 + k22;    // z1 - z5 - z2 + z6
}

static void imdct_step3_inner_s_loop_ld654(int n, float *e, int i_off, float *A, int base_n)
{
    int a_off = base_n >> 3;
    float A2 = A[0 + a_off];
    float *z = e + i_off;
    float *base = z - 16 * n;

    while (z > base) {
        float k00, k11;

        k00 = z[-0] - z[-8];
        k11 = z[-1] - z[-9];
        z[-0] = z[-0] + z[-8];
        z[-1] = z[-1] + z[-9];
        z[-8] = k00;
        z[-9] = k11;

        k00 = z[-2] - z[-10];
        k11 = z[-3] - z[-11];
        z[-2] = z[-2] + z[-10];
        z[-3] = z[-3] + z[-11];
        z[-10] = (k00 + k11) * A2;
        z[-11] = (k11 - k00) * A2;

        k00 = z[-12] - z[-4];  // reverse to avoid a unary negation
        k11 = z[-5] - z[-13];
        z[-4] = z[-4] + z[-12];
        z[-5] = z[-5] + z[-13];
        z[-12] = k11;
        z[-13] = k00;

        k00 = z[-14] - z[-6];  // reverse to avoid a unary negation
        k11 = z[-7] - z[-15];
        z[-6] = z[-6] + z[-14];
        z[-7] = z[-7] + z[-15];
        z[-14] = (k00 + k11) * A2;
        z[-15] = (k00 - k11) * A2;

        iter_54(z);
        iter_54(z - 8);
        z -= 16;
    }
}

static void inverse_mdct(float *buffer, int n, vorb *f, int blocktype)
{
    int n2 = n >> 1, n4 = n >> 2, n8 = n >> 3, l;
    int ld;
    // @OPTIMIZE: reduce register pressure by using fewer variables?
    int save_point = temp_alloc_save(f);
    float *buf2 = (float *)temp_alloc(f, n2 * sizeof(*buf2));
    float *u = NULL, *v = NULL;
    // twiddle factors
    float *A = f->A[blocktype];

    // IMDCT algorithm from "The use of multirate filter banks for coding of high quality digital audio"
    // See notes about bugs in that paper in less-optimal implementation 'inverse_mdct_old' after this function.

    // kernel from paper


    // merged:
    //   copy and reflect spectral data
    //   step 0

    // note that it turns out that the items added together during
    // this step are, in fact, being added to themselves (as reflected
    // by step 0). inexplicable inefficiency! this became obvious
    // once I combined the passes.

    // so there's a missing 'times 2' here (for adding X to itself).
    // this propogates through linearly to the end, where the numbers
    // are 1/2 too small, and need to be compensated for.

    {
        float *d, *e, *AA, *e_stop;
        d = &buf2[n2 - 2];
        AA = A;
        e = &buffer[0];
        e_stop = &buffer[n2];
        while (e != e_stop) {
            d[1] = (e[0] * AA[0] - e[2] * AA[1]);
            d[0] = (e[0] * AA[1] + e[2] * AA[0]);
            d -= 2;
            AA += 2;
            e += 4;
        }

        e = &buffer[n2 - 3];
        while (d >= buf2) {
            d[1] = (-e[2] * AA[0] - -e[0] * AA[1]);
            d[0] = (-e[2] * AA[1] + -e[0] * AA[0]);
            d -= 2;
            AA += 2;
            e -= 4;
        }
    }

    // now we use symbolic names for these, so that we can
    // possibly swap their meaning as we change which operations
    // are in place

    u = buffer;
    v = buf2;

    // step 2    (paper output is w, now u)
    // this could be in place, but the data ends up in the wrong
    // place... _somebody_'s got to swap it, so this is nominated
    {
        float *AA = &A[n2 - 8];
        float *d0, *d1, *e0, *e1;

        e0 = &v[n4];
        e1 = &v[0];

        d0 = &u[n4];
        d1 = &u[0];

        while (AA >= A) {
            float v40_20, v41_21;

            v41_21 = e0[1] - e1[1];
            v40_20 = e0[0] - e1[0];
            d0[1] = e0[1] + e1[1];
            d0[0] = e0[0] + e1[0];
            d1[1] = v41_21*AA[4] - v40_20*AA[5];
            d1[0] = v40_20*AA[4] + v41_21*AA[5];

            v41_21 = e0[3] - e1[3];
            v40_20 = e0[2] - e1[2];
            d0[3] = e0[3] + e1[3];
            d0[2] = e0[2] + e1[2];
            d1[3] = v41_21*AA[0] - v40_20*AA[1];
            d1[2] = v40_20*AA[0] + v41_21*AA[1];

            AA -= 8;

            d0 += 4;
            d1 += 4;
            e0 += 4;
            e1 += 4;
        }
    }

    // step 3
    ld = ilog(n) - 1; // ilog is off-by-one from normal definitions

                      // optimized step 3:

                      // the original step3 loop can be nested r inside s or s inside r;
                      // it's written originally as s inside r, but this is dumb when r
                      // iterates many times, and s few. So I have two copies of it and
                      // switch between them halfway.

                      // this is iteration 0 of step 3
    imdct_step3_iter0_loop(n >> 4, u, n2 - 1 - n4 * 0, -(n >> 3), A);
    imdct_step3_iter0_loop(n >> 4, u, n2 - 1 - n4 * 1, -(n >> 3), A);

    // this is iteration 1 of step 3
    imdct_step3_inner_r_loop(n >> 5, u, n2 - 1 - n8 * 0, -(n >> 4), A, 16);
    imdct_step3_inner_r_loop(n >> 5, u, n2 - 1 - n8 * 1, -(n >> 4), A, 16);
    imdct_step3_inner_r_loop(n >> 5, u, n2 - 1 - n8 * 2, -(n >> 4), A, 16);
    imdct_step3_inner_r_loop(n >> 5, u, n2 - 1 - n8 * 3, -(n >> 4), A, 16);

    l = 2;
    for (; l < (ld - 3) >> 1; ++l) {
        int k0 = n >> (l + 2), k0_2 = k0 >> 1;
        int lim = 1 << (l + 1);
        int i;
        for (i = 0; i < lim; ++i)
            imdct_step3_inner_r_loop(n >> (l + 4), u, n2 - 1 - k0*i, -k0_2, A, 1 << (l + 3));
    }

    for (; l < ld - 6; ++l) {
        int k0 = n >> (l + 2), k1 = 1 << (l + 3), k0_2 = k0 >> 1;
        int rlim = n >> (l + 6), r;
        int lim = 1 << (l + 1);
        int i_off;
        float *A0 = A;
        i_off = n2 - 1;
        for (r = rlim; r > 0; --r) {
            imdct_step3_inner_s_loop(lim, u, i_off, -k0_2, A0, k1, k0);
            A0 += k1 * 4;
            i_off -= 8;
        }
    }

    // iterations with count:
    //   ld-6,-5,-4 all interleaved together
    //       the big win comes from getting rid of needless flops
    //         due to the constants on pass 5 & 4 being all 1 and 0;
    //       combining them to be simultaneous to improve cache made little difference
    imdct_step3_inner_s_loop_ld654(n >> 5, u, n2 - 1, A, n);

    // output is u

    // step 4, 5, and 6
    // cannot be in-place because of step 5
    {
        uint16 *bitrev = f->bit_reverse[blocktype];
        // weirdly, I'd have thought reading sequentially and writing
        // erratically would have been better than vice-versa, but in
        // fact that's not what my testing showed. (That is, with
        // j = bitreverse(i), do you read i and write j, or read j and write i.)

        float *d0 = &v[n4 - 4];
        float *d1 = &v[n2 - 4];
        while (d0 >= v) {
            int k4;

            k4 = bitrev[0];
            d1[3] = u[k4 + 0];
            d1[2] = u[k4 + 1];
            d0[3] = u[k4 + 2];
            d0[2] = u[k4 + 3];

            k4 = bitrev[1];
            d1[1] = u[k4 + 0];
            d1[0] = u[k4 + 1];
            d0[1] = u[k4 + 2];
            d0[0] = u[k4 + 3];

            d0 -= 4;
            d1 -= 4;
            bitrev += 2;
        }
    }
    // (paper output is u, now v)


    // data must be in buf2
    assert(v == buf2);

    // step 7   (paper output is v, now v)
    // this is now in place
    {
        float *C = f->C[blocktype];
        float *d, *e;

        d = v;
        e = v + n2 - 4;

        while (d < e) {
            float a02, a11, b0, b1, b2, b3;

            a02 = d[0] - e[2];
            a11 = d[1] + e[3];

            b0 = C[1] * a02 + C[0] * a11;
            b1 = C[1] * a11 - C[0] * a02;

            b2 = d[0] + e[2];
            b3 = d[1] - e[3];

            d[0] = b2 + b0;
            d[1] = b3 + b1;
            e[2] = b2 - b0;
            e[3] = b1 - b3;

            a02 = d[2] - e[0];
            a11 = d[3] + e[1];

            b0 = C[3] * a02 + C[2] * a11;
            b1 = C[3] * a11 - C[2] * a02;

            b2 = d[2] + e[0];
            b3 = d[3] - e[1];

            d[2] = b2 + b0;
            d[3] = b3 + b1;
            e[0] = b2 - b0;
            e[1] = b1 - b3;

            C += 4;
            d += 4;
            e -= 4;
        }
    }

    // data must be in buf2


    // step 8+decode   (paper output is X, now buffer)
    // this generates pairs of data a la 8 and pushes them directly through
    // the decode kernel (pushing rather than pulling) to avoid having
    // to make another pass later

    // this cannot POSSIBLY be in place, so we refer to the buffers directly

    {
        float *d0, *d1, *d2, *d3;

        float *B = f->B[blocktype] + n2 - 8;
        float *e = buf2 + n2 - 8;
        d0 = &buffer[0];
        d1 = &buffer[n2 - 4];
        d2 = &buffer[n2];
        d3 = &buffer[n - 4];
        while (e >= v) {
            float p0, p1, p2, p3;

            p3 = e[6] * B[7] - e[7] * B[6];
            p2 = -e[6] * B[6] - e[7] * B[7];

            d0[0] = p3;
            d1[3] = -p3;
            d2[0] = p2;
            d3[3] = p2;

            p1 = e[4] * B[5] - e[5] * B[4];
            p0 = -e[4] * B[4] - e[5] * B[5];

            d0[1] = p1;
            d1[2] = -p1;
            d2[1] = p0;
            d3[2] = p0;

            p3 = e[2] * B[3] - e[3] * B[2];
            p2 = -e[2] * B[2] - e[3] * B[3];

            d0[2] = p3;
            d1[1] = -p3;
            d2[2] = p2;
            d3[1] = p2;

            p1 = e[0] * B[1] - e[1] * B[0];
            p0 = -e[0] * B[0] - e[1] * B[1];

            d0[3] = p1;
            d1[0] = -p1;
            d2[3] = p0;
            d3[0] = p0;

            B -= 8;
            e -= 8;
            d0 += 4;
            d2 += 4;
            d1 -= 4;
            d3 -= 4;
        }
    }

    temp_alloc_restore(f, save_point);
}

#if 0
// this is the original version of the above code, if you want to optimize it from scratch
void inverse_mdct_naive(float *buffer, int n)
{
    float s;
    float A[1 << 12], B[1 << 12], C[1 << 11];
    int i, k, k2, k4, n2 = n >> 1, n4 = n >> 2, n8 = n >> 3, l;
    int n3_4 = n - n4, ld;
    // how can they claim this only uses N words?!
    // oh, because they're only used sparsely, whoops
    float u[1 << 13], X[1 << 13], v[1 << 13], w[1 << 13];
    // set up twiddle factors

    for (k = k2 = 0; k < n4; ++k, k2 += 2) {
        A[k2] = (float)cos(4 * k*M_PI / n);
        A[k2 + 1] = (float)-sin(4 * k*M_PI / n);
        B[k2] = (float)cos((k2 + 1)*M_PI / n / 2);
        B[k2 + 1] = (float)sin((k2 + 1)*M_PI / n / 2);
    }
    for (k = k2 = 0; k < n8; ++k, k2 += 2) {
        C[k2] = (float)cos(2 * (k2 + 1)*M_PI / n);
        C[k2 + 1] = (float)-sin(2 * (k2 + 1)*M_PI / n);
    }

    // IMDCT algorithm from "The use of multirate filter banks for coding of high quality digital audio"
    // Note there are bugs in that pseudocode, presumably due to them attempting
    // to rename the arrays nicely rather than representing the way their actual
    // implementation bounces buffers back and forth. As a result, even in the
    // "some formulars corrected" version, a direct implementation fails. These
    // are noted below as "paper bug".

    // copy and reflect spectral data
    for (k = 0; k < n2; ++k) u[k] = buffer[k];
    for (; k < n; ++k) u[k] = -buffer[n - k - 1];
    // kernel from paper
    // step 1
    for (k = k2 = k4 = 0; k < n4; k += 1, k2 += 2, k4 += 4) {
        v[n - k4 - 1] = (u[k4] - u[n - k4 - 1]) * A[k2] - (u[k4 + 2] - u[n - k4 - 3])*A[k2 + 1];
        v[n - k4 - 3] = (u[k4] - u[n - k4 - 1]) * A[k2 + 1] + (u[k4 + 2] - u[n - k4 - 3])*A[k2];
    }
    // step 2
    for (k = k4 = 0; k < n8; k += 1, k4 += 4) {
        w[n2 + 3 + k4] = v[n2 + 3 + k4] + v[k4 + 3];
        w[n2 + 1 + k4] = v[n2 + 1 + k4] + v[k4 + 1];
        w[k4 + 3] = (v[n2 + 3 + k4] - v[k4 + 3])*A[n2 - 4 - k4] - (v[n2 + 1 + k4] - v[k4 + 1])*A[n2 - 3 - k4];
        w[k4 + 1] = (v[n2 + 1 + k4] - v[k4 + 1])*A[n2 - 4 - k4] + (v[n2 + 3 + k4] - v[k4 + 3])*A[n2 - 3 - k4];
    }
    // step 3
    ld = ilog(n) - 1; // ilog is off-by-one from normal definitions
    for (l = 0; l < ld - 3; ++l) {
        int k0 = n >> (l + 2), k1 = 1 << (l + 3);
        int rlim = n >> (l + 4), r4, r;
        int s2lim = 1 << (l + 2), s2;
        for (r = r4 = 0; r < rlim; r4 += 4, ++r) {
            for (s2 = 0; s2 < s2lim; s2 += 2) {
                u[n - 1 - k0*s2 - r4] = w[n - 1 - k0*s2 - r4] + w[n - 1 - k0*(s2 + 1) - r4];
                u[n - 3 - k0*s2 - r4] = w[n - 3 - k0*s2 - r4] + w[n - 3 - k0*(s2 + 1) - r4];
                u[n - 1 - k0*(s2 + 1) - r4] = (w[n - 1 - k0*s2 - r4] - w[n - 1 - k0*(s2 + 1) - r4]) * A[r*k1]
                    - (w[n - 3 - k0*s2 - r4] - w[n - 3 - k0*(s2 + 1) - r4]) * A[r*k1 + 1];
                u[n - 3 - k0*(s2 + 1) - r4] = (w[n - 3 - k0*s2 - r4] - w[n - 3 - k0*(s2 + 1) - r4]) * A[r*k1]
                    + (w[n - 1 - k0*s2 - r4] - w[n - 1 - k0*(s2 + 1) - r4]) * A[r*k1 + 1];
            }
        }
        if (l + 1 < ld - 3) {
            // paper bug: ping-ponging of u&w here is omitted
            memcpy(w, u, sizeof(u));
        }
    }

    // step 4
    for (i = 0; i < n8; ++i) {
        int j = bit_reverse(i) >> (32 - ld + 3);
        assert(j < n8);
        if (i == j) {
            // paper bug: original code probably swapped in place; if copying,
            //            need to directly copy in this case
            int i8 = i << 3;
            v[i8 + 1] = u[i8 + 1];
            v[i8 + 3] = u[i8 + 3];
            v[i8 + 5] = u[i8 + 5];
            v[i8 + 7] = u[i8 + 7];
        }
        else if (i < j) {
            int i8 = i << 3, j8 = j << 3;
            v[j8 + 1] = u[i8 + 1], v[i8 + 1] = u[j8 + 1];
            v[j8 + 3] = u[i8 + 3], v[i8 + 3] = u[j8 + 3];
            v[j8 + 5] = u[i8 + 5], v[i8 + 5] = u[j8 + 5];
            v[j8 + 7] = u[i8 + 7], v[i8 + 7] = u[j8 + 7];
        }
    }
    // step 5
    for (k = 0; k < n2; ++k) {
        w[k] = v[k * 2 + 1];
    }
    // step 6
    for (k = k2 = k4 = 0; k < n8; ++k, k2 += 2, k4 += 4) {
        u[n - 1 - k2] = w[k4];
        u[n - 2 - k2] = w[k4 + 1];
        u[n3_4 - 1 - k2] = w[k4 + 2];
        u[n3_4 - 2 - k2] = w[k4 + 3];
    }
    // step 7
    for (k = k2 = 0; k < n8; ++k, k2 += 2) {
        v[n2 + k2] = (u[n2 + k2] + u[n - 2 - k2] + C[k2 + 1] * (u[n2 + k2] - u[n - 2 - k2]) + C[k2] * (u[n2 + k2 + 1] + u[n - 2 - k2 + 1])) / 2;
        v[n - 2 - k2] = (u[n2 + k2] + u[n - 2 - k2] - C[k2 + 1] * (u[n2 + k2] - u[n - 2 - k2]) - C[k2] * (u[n2 + k2 + 1] + u[n - 2 - k2 + 1])) / 2;
        v[n2 + 1 + k2] = (u[n2 + 1 + k2] - u[n - 1 - k2] + C[k2 + 1] * (u[n2 + 1 + k2] + u[n - 1 - k2]) - C[k2] * (u[n2 + k2] - u[n - 2 - k2])) / 2;
        v[n - 1 - k2] = (-u[n2 + 1 + k2] + u[n - 1 - k2] + C[k2 + 1] * (u[n2 + 1 + k2] + u[n - 1 - k2]) - C[k2] * (u[n2 + k2] - u[n - 2 - k2])) / 2;
    }
    // step 8
    for (k = k2 = 0; k < n4; ++k, k2 += 2) {
        X[k] = v[k2 + n2] * B[k2] + v[k2 + 1 + n2] * B[k2 + 1];
        X[n2 - 1 - k] = v[k2 + n2] * B[k2 + 1] - v[k2 + 1 + n2] * B[k2];
    }

    // decode kernel to output
    // determined the following value experimentally
    // (by first figuring out what made inverse_mdct_slow work); then matching that here
    // (probably vorbis encoder premultiplies by n or n/2, to save it on the decoder?)
    s = 0.5; // theoretically would be n4

             // [[[ note! the s value of 0.5 is compensated for by the B[] in the current code,
             //     so it needs to use the "old" B values to behave correctly, or else
             //     set s to 1.0 ]]]
    for (i = 0; i < n4; ++i) buffer[i] = s * X[i + n4];
    for (; i < n3_4; ++i) buffer[i] = -s * X[n3_4 - i - 1];
    for (; i < n; ++i) buffer[i] = -s * X[i - n3_4];
}
#endif

static float *get_window(vorb *f, int len)
{
    len <<= 1;
    if (len == f->blocksize_0) return f->window[0];
    if (len == f->blocksize_1) return f->window[1];
    assert(0);
    return NULL;
}

#ifndef STB_VORBIS_NO_DEFER_FLOOR
typedef int16 YTYPE;
#else
typedef int YTYPE;
#endif
static int do_floor(vorb *f, Mapping *map, int i, int n, float *target, YTYPE *finalY, uint8 *step2_flag)
{
    int n2 = n >> 1;
    int s = map->chan[i].mux, floor;
    floor = map->submap_floor[s];
    if (f->floor_types[floor] == 0) {
        return error(f, VORBIS_invalid_stream);
    }
    else {
        Floor1 *g = &f->floor_config[floor].floor1;
        int j, q;
        int lx = 0, ly = finalY[0] * g->floor1_multiplier;
        for (q = 1; q < g->values; ++q) {
            j = g->sorted_order[q];
#ifndef STB_VORBIS_NO_DEFER_FLOOR
            if (finalY[j] >= 0)
#else
            if (step2_flag[j])
#endif
            {
                int hy = finalY[j] * g->floor1_multiplier;
                int hx = g->Xlist[j];
                if (lx != hx)
                    draw_line(target, lx, ly, hx, hy, n2);
                CHECK(f);
                lx = hx, ly = hy;
            }
        }
        if (lx < n2) {
            // optimization of: draw_line(target, lx,ly, n,ly, n2);
            for (j = lx; j < n2; ++j)
                LINE_OP(target[j], inverse_db_table[ly]);
            CHECK(f);
        }
    }
    return TRUE;
}

// The meaning of "left" and "right"
//
// For a given frame:
//     we compute samples from 0..n
//     window_center is n/2
//     we'll window and mix the samples from left_start to left_end with data from the previous frame
//     all of the samples from left_end to right_start can be output without mixing; however,
//        this interval is 0-length except when transitioning between short and long frames
//     all of the samples from right_start to right_end need to be mixed with the next frame,
//        which we don't have, so those get saved in a buffer
//     frame N's right_end-right_start, the number of samples to mix with the next frame,
//        has to be the same as frame N+1's left_end-left_start (which they are by
//        construction)

static int vorbis_decode_initial(vorb *f, int *p_left_start, int *p_left_end, int *p_right_start, int *p_right_end, int *mode)
{
    Mode *m;
    int i, n, prev, next, window_center;
    f->channel_buffer_start = f->channel_buffer_end = 0;

retry:
    if (f->eof) return FALSE;
    if (!maybe_start_packet(f))
        return FALSE;
    // check packet type
    if (get_bits(f, 1) != 0) {
        if (IS_PUSH_MODE(f))
            return error(f, VORBIS_bad_packet_type);
        while (EOP != get8_packet(f));
        goto retry;
    }

    if (f->alloc.alloc_buffer)
        assert(f->alloc.alloc_buffer_length_in_bytes == f->temp_offset);

    i = get_bits(f, ilog(f->mode_count - 1));
    if (i == EOP) return FALSE;
    if (i >= f->mode_count) return FALSE;
    *mode = i;
    m = f->mode_config + i;
    if (m->blockflag) {
        n = f->blocksize_1;
        prev = get_bits(f, 1);
        next = get_bits(f, 1);
    }
    else {
        prev = next = 0;
        n = f->blocksize_0;
    }

    // WINDOWING

    window_center = n >> 1;
    if (m->blockflag && !prev) {
        *p_left_start = (n - f->blocksize_0) >> 2;
        *p_left_end = (n + f->blocksize_0) >> 2;
    }
    else {
        *p_left_start = 0;
        *p_left_end = window_center;
    }
    if (m->blockflag && !next) {
        *p_right_start = (n * 3 - f->blocksize_0) >> 2;
        *p_right_end = (n * 3 + f->blocksize_0) >> 2;
    }
    else {
        *p_right_start = window_center;
        *p_right_end = n;
    }

    return TRUE;
}

static int vorbis_decode_packet_rest(vorb *f, int *len, Mode *m, int left_start, int left_end, int right_start, int right_end, int *p_left)
{
    Mapping *map;
    int i, j, k, n, n2;
    int zero_channel[256];
    int really_zero_channel[256];

    // WINDOWING

    n = f->blocksize[m->blockflag];
    map = &f->mapping[m->mapping];

    // FLOORS
    n2 = n >> 1;

    CHECK(f);

    for (i = 0; i < f->channels; ++i) {
        int s = map->chan[i].mux, floor;
        zero_channel[i] = FALSE;
        floor = map->submap_floor[s];
        if (f->floor_types[floor] == 0) {
            return error(f, VORBIS_invalid_stream);
        }
        else {
            Floor1 *g = &f->floor_config[floor].floor1;
            if (get_bits(f, 1)) {
                short *finalY;
                uint8 step2_flag[256];
                static int range_list[4] = { 256, 128, 86, 64 };
                int range = range_list[g->floor1_multiplier - 1];
                int offset = 2;
                finalY = f->finalY[i];
                finalY[0] = get_bits(f, ilog(range) - 1);
                finalY[1] = get_bits(f, ilog(range) - 1);
                for (j = 0; j < g->partitions; ++j) {
                    int pclass = g->partition_class_list[j];
                    int cdim = g->class_dimensions[pclass];
                    int cbits = g->class_subclasses[pclass];
                    int csub = (1 << cbits) - 1;
                    int cval = 0;
                    if (cbits) {
                        Codebook *c = f->codebooks + g->class_masterbooks[pclass];
                        DECODE(cval, f, c);
                    }
                    for (k = 0; k < cdim; ++k) {
                        int book = g->subclass_books[pclass][cval & csub];
                        cval = cval >> cbits;
                        if (book >= 0) {
                            int temp;
                            Codebook *c = f->codebooks + book;
                            DECODE(temp, f, c);
                            finalY[offset++] = temp;
                        }
                        else
                            finalY[offset++] = 0;
                    }
                }
                if (f->valid_bits == INVALID_BITS) goto error; // behavior according to spec
                step2_flag[0] = step2_flag[1] = 1;
                for (j = 2; j < g->values; ++j) {
                    int low, high, pred, highroom, lowroom, room, val;
                    low = g->neighbors[j][0];
                    high = g->neighbors[j][1];
                    //neighbors(g->Xlist, j, &low, &high);
                    pred = predict_point(g->Xlist[j], g->Xlist[low], g->Xlist[high], finalY[low], finalY[high]);
                    val = finalY[j];
                    highroom = range - pred;
                    lowroom = pred;
                    if (highroom < lowroom)
                        room = highroom * 2;
                    else
                        room = lowroom * 2;
                    if (val) {
                        step2_flag[low] = step2_flag[high] = 1;
                        step2_flag[j] = 1;
                        if (val >= room)
                            if (highroom > lowroom)
                                finalY[j] = val - lowroom + pred;
                            else
                                finalY[j] = pred - val + highroom - 1;
                        else
                            if (val & 1)
                                finalY[j] = pred - ((val + 1) >> 1);
                            else
                                finalY[j] = pred + (val >> 1);
                    }
                    else {
                        step2_flag[j] = 0;
                        finalY[j] = pred;
                    }
                }

#ifdef STB_VORBIS_NO_DEFER_FLOOR
                do_floor(f, map, i, n, f->floor_buffers[i], finalY, step2_flag);
#else
                // defer final floor computation until _after_ residue
                for (j = 0; j < g->values; ++j) {
                    if (!step2_flag[j])
                        finalY[j] = -1;
                }
#endif
            }
            else {
            error:
                zero_channel[i] = TRUE;
            }
            // So we just defer everything else to later

            // at this point we've decoded the floor into buffer
        }
    }
    CHECK(f);
    // at this point we've decoded all floors

    if (f->alloc.alloc_buffer)
        assert(f->alloc.alloc_buffer_length_in_bytes == f->temp_offset);

    // re-enable coupled channels if necessary
    memcpy(really_zero_channel, zero_channel, sizeof(really_zero_channel[0]) * f->channels);
    for (i = 0; i < map->coupling_steps; ++i)
        if (!zero_channel[map->chan[i].magnitude] || !zero_channel[map->chan[i].angle]) {
            zero_channel[map->chan[i].magnitude] = zero_channel[map->chan[i].angle] = FALSE;
        }

    CHECK(f);
    // RESIDUE DECODE
    for (i = 0; i < map->submaps; ++i) {
        float *residue_buffers[STB_VORBIS_MAX_CHANNELS];
        int r;
        uint8 do_not_decode[256];
        int ch = 0;
        for (j = 0; j < f->channels; ++j) {
            if (map->chan[j].mux == i) {
                if (zero_channel[j]) {
                    do_not_decode[ch] = TRUE;
                    residue_buffers[ch] = NULL;
                }
                else {
                    do_not_decode[ch] = FALSE;
                    residue_buffers[ch] = f->channel_buffers[j];
                }
                ++ch;
            }
        }
        r = map->submap_residue[i];
        decode_residue(f, residue_buffers, ch, n2, r, do_not_decode);
    }

    if (f->alloc.alloc_buffer)
        assert(f->alloc.alloc_buffer_length_in_bytes == f->temp_offset);
    CHECK(f);

    // INVERSE COUPLING
    for (i = map->coupling_steps - 1; i >= 0; --i) {
        int n2 = n >> 1;
        float *m = f->channel_buffers[map->chan[i].magnitude];
        float *a = f->channel_buffers[map->chan[i].angle];
        for (j = 0; j < n2; ++j) {
            float a2, m2;
            if (m[j] > 0)
                if (a[j] > 0)
                    m2 = m[j], a2 = m[j] - a[j];
                else
                    a2 = m[j], m2 = m[j] + a[j];
            else
                if (a[j] > 0)
                    m2 = m[j], a2 = m[j] + a[j];
                else
                    a2 = m[j], m2 = m[j] - a[j];
            m[j] = m2;
            a[j] = a2;
        }
    }
    CHECK(f);

    // finish decoding the floors
#ifndef STB_VORBIS_NO_DEFER_FLOOR
    for (i = 0; i < f->channels; ++i) {
        if (really_zero_channel[i]) {
            memset(f->channel_buffers[i], 0, sizeof(*f->channel_buffers[i]) * n2);
        }
        else {
            do_floor(f, map, i, n, f->channel_buffers[i], f->finalY[i], NULL);
        }
    }
#else
    for (i = 0; i < f->channels; ++i) {
        if (really_zero_channel[i]) {
            memset(f->channel_buffers[i], 0, sizeof(*f->channel_buffers[i]) * n2);
        }
        else {
            for (j = 0; j < n2; ++j)
                f->channel_buffers[i][j] *= f->floor_buffers[i][j];
        }
    }
#endif

    // INVERSE MDCT
    CHECK(f);
    for (i = 0; i < f->channels; ++i)
        inverse_mdct(f->channel_buffers[i], n, f, m->blockflag);
    CHECK(f);

    // this shouldn't be necessary, unless we exited on an error
    // and want to flush to get to the next packet
    flush_packet(f);

    if (f->first_decode) {
        // assume we start so first non-discarded sample is sample 0
        // this isn't to spec, but spec would require us to read ahead
        // and decode the size of all current frames--could be done,
        // but presumably it's not a commonly used feature
        f->current_loc = -n2; // start of first frame is positioned for discard
                              // we might have to discard samples "from" the next frame too,
                              // if we're lapping a large block then a small at the start?
        f->discard_samples_deferred = n - right_end;
        f->current_loc_valid = TRUE;
        f->first_decode = FALSE;
    }
    else if (f->discard_samples_deferred) {
        if (f->discard_samples_deferred >= right_start - left_start) {
            f->discard_samples_deferred -= (right_start - left_start);
            left_start = right_start;
            *p_left = left_start;
        }
        else {
            left_start += f->discard_samples_deferred;
            *p_left = left_start;
            f->discard_samples_deferred = 0;
        }
    }
    else if (f->previous_length == 0 && f->current_loc_valid) {
        // we're recovering from a seek... that means we're going to discard
        // the samples from this packet even though we know our position from
        // the last page header, so we need to update the position based on
        // the discarded samples here
        // but wait, the code below is going to add this in itself even
        // on a discard, so we don't need to do it here...
    }

    // check if we have ogg information about the sample # for this packet
    if (f->last_seg_which == f->end_seg_with_known_loc) {
        // if we have a valid current loc, and this is final:
        if (f->current_loc_valid && (f->page_flag & PAGEFLAG_last_page)) {
            uint32 current_end = f->known_loc_for_packet - (n - right_end);
            // then let's infer the size of the (probably) short final frame
            if (current_end < f->current_loc + (right_end - left_start)) {
                if (current_end < f->current_loc) {
                    // negative truncation, that's impossible!
                    *len = 0;
                }
                else {
                    *len = current_end - f->current_loc;
                }
                *len += left_start;
                if (*len > right_end) *len = right_end; // this should never happen
                f->current_loc += *len;
                return TRUE;
            }
        }
        // otherwise, just set our sample loc
        // guess that the ogg granule pos refers to the _middle_ of the
        // last frame?
        // set f->current_loc to the position of left_start
        f->current_loc = f->known_loc_for_packet - (n2 - left_start);
        f->current_loc_valid = TRUE;
    }
    if (f->current_loc_valid)
        f->current_loc += (right_start - left_start);

    if (f->alloc.alloc_buffer)
        assert(f->alloc.alloc_buffer_length_in_bytes == f->temp_offset);
    *len = right_end;  // ignore samples after the window goes to 0
    CHECK(f);

    return TRUE;
}

static int vorbis_decode_packet(vorb *f, int *len, int *p_left, int *p_right)
{
    int mode, left_end, right_end;
    if (!vorbis_decode_initial(f, p_left, &left_end, p_right, &right_end, &mode)) return 0;
    return vorbis_decode_packet_rest(f, len, f->mode_config + mode, *p_left, left_end, *p_right, right_end, p_left);
}

static int vorbis_finish_frame(stb_vorbis *f, int len, int left, int right)
{
    int prev, i, j;
    // we use right&left (the start of the right- and left-window sin()-regions)
    // to determine how much to return, rather than inferring from the rules
    // (same result, clearer code); 'left' indicates where our sin() window
    // starts, therefore where the previous window's right edge starts, and
    // therefore where to start mixing from the previous buffer. 'right'
    // indicates where our sin() ending-window starts, therefore that's where
    // we start saving, and where our returned-data ends.

    // mixin from previous window
    if (f->previous_length) {
        int i, j, n = f->previous_length;
        float *w = get_window(f, n);
        for (i = 0; i < f->channels; ++i) {
            for (j = 0; j < n; ++j)
                f->channel_buffers[i][left + j] =
                f->channel_buffers[i][left + j] * w[j] +
                f->previous_window[i][j] * w[n - 1 - j];
        }
    }

    prev = f->previous_length;

    // last half of this data becomes previous window
    f->previous_length = len - right;

    // @OPTIMIZE: could avoid this copy by double-buffering the
    // output (flipping previous_window with channel_buffers), but
    // then previous_window would have to be 2x as large, and
    // channel_buffers couldn't be temp mem (although they're NOT
    // currently temp mem, they could be (unless we want to level
    // performance by spreading out the computation))
    for (i = 0; i < f->channels; ++i)
        for (j = 0; right + j < len; ++j)
            f->previous_window[i][j] = f->channel_buffers[i][right + j];

    if (!prev)
        // there was no previous packet, so this data isn't valid...
        // this isn't entirely true, only the would-have-overlapped data
        // isn't valid, but this seems to be what the spec requires
        return 0;

    // truncate a short frame
    if (len < right) right = len;

    f->samples_output += right - left;

    return right - left;
}

static void vorbis_pump_first_frame(stb_vorbis *f)
{
    int len, right, left;
    if (vorbis_decode_packet(f, &len, &left, &right))
        vorbis_finish_frame(f, len, left, right);
}

#ifndef STB_VORBIS_NO_PUSHDATA_API
static int is_whole_packet_present(stb_vorbis *f, int end_page)
{
    // make sure that we have the packet available before continuing...
    // this requires a full ogg parse, but we know we can fetch from f->stream

    // instead of coding this out explicitly, we could save the current read state,
    // read the next packet with get8() until end-of-packet, check f->eof, then
    // reset the state? but that would be slower, esp. since we'd have over 256 bytes
    // of state to restore (primarily the page segment table)

    int s = f->next_seg, first = TRUE;
    uint8 *p = f->stream;

    if (s != -1) { // if we're not starting the packet with a 'continue on next page' flag
        for (; s < f->segment_count; ++s) {
            p += f->segments[s];
            if (f->segments[s] < 255)               // stop at first short segment
                break;
        }
        // either this continues, or it ends it...
        if (end_page)
            if (s < f->segment_count - 1)             return error(f, VORBIS_invalid_stream);
        if (s == f->segment_count)
            s = -1; // set 'crosses page' flag
        if (p > f->stream_end)                     return error(f, VORBIS_need_more_data);
        first = FALSE;
    }
    for (; s == -1;) {
        uint8 *q;
        int n;

        // check that we have the page header ready
        if (p + 26 >= f->stream_end)               return error(f, VORBIS_need_more_data);
        // validate the page
        if (memcmp(p, ogg_page_header, 4))         return error(f, VORBIS_invalid_stream);
        if (p[4] != 0)                             return error(f, VORBIS_invalid_stream);
        if (first) { // the first segment must NOT have 'continued_packet', later ones MUST
            if (f->previous_length)
                if ((p[5] & PAGEFLAG_continued_packet))  return error(f, VORBIS_invalid_stream);
            // if no previous length, we're resynching, so we can come in on a continued-packet,
            // which we'll just drop
        }
        else {
            if (!(p[5] & PAGEFLAG_continued_packet)) return error(f, VORBIS_invalid_stream);
        }
        n = p[26]; // segment counts
        q = p + 27;  // q points to segment table
        p = q + n; // advance past header
                   // make sure we've read the segment table
        if (p > f->stream_end)                     return error(f, VORBIS_need_more_data);
        for (s = 0; s < n; ++s) {
            p += q[s];
            if (q[s] < 255)
                break;
        }
        if (end_page)
            if (s < n - 1)                            return error(f, VORBIS_invalid_stream);
        if (s == n)
            s = -1; // set 'crosses page' flag
        if (p > f->stream_end)                     return error(f, VORBIS_need_more_data);
        first = FALSE;
    }
    return TRUE;
}
#endif // !STB_VORBIS_NO_PUSHDATA_API

static int start_decoder(vorb *f)
{
    uint8 header[6], x, y;
    int len, i, j, k, max_submaps = 0;
    int longest_floorlist = 0;

    // first page, first packet

    if (!start_page(f))                              return FALSE;
    // validate page flag
    if (!(f->page_flag & PAGEFLAG_first_page))       return error(f, VORBIS_invalid_first_page);
    if (f->page_flag & PAGEFLAG_last_page)           return error(f, VORBIS_invalid_first_page);
    if (f->page_flag & PAGEFLAG_continued_packet)    return error(f, VORBIS_invalid_first_page);
    // check for expected packet length
    if (f->segment_count != 1)                       return error(f, VORBIS_invalid_first_page);
    if (f->segments[0] != 30)                        return error(f, VORBIS_invalid_first_page);
    // read packet
    // check packet header
    if (get8(f) != VORBIS_packet_id)                 return error(f, VORBIS_invalid_first_page);
    if (!getn(f, header, 6))                         return error(f, VORBIS_unexpected_eof);
    if (!vorbis_validate(header))                    return error(f, VORBIS_invalid_first_page);
    // vorbis_version
    if (get32(f) != 0)                               return error(f, VORBIS_invalid_first_page);
    f->channels = get8(f); if (!f->channels)         return error(f, VORBIS_invalid_first_page);
    if (f->channels > STB_VORBIS_MAX_CHANNELS)       return error(f, VORBIS_too_many_channels);
    f->sample_rate = get32(f); if (!f->sample_rate)  return error(f, VORBIS_invalid_first_page);
    get32(f); // bitrate_maximum
    get32(f); // bitrate_nominal
    get32(f); // bitrate_minimum
    x = get8(f);
    {
        int log0, log1;
        log0 = x & 15;
        log1 = x >> 4;
        f->blocksize_0 = 1 << log0;
        f->blocksize_1 = 1 << log1;
        if (log0 < 6 || log0 > 13)                       return error(f, VORBIS_invalid_setup);
        if (log1 < 6 || log1 > 13)                       return error(f, VORBIS_invalid_setup);
        if (log0 > log1)                                 return error(f, VORBIS_invalid_setup);
    }

    // framing_flag
    x = get8(f);
    if (!(x & 1))                                    return error(f, VORBIS_invalid_first_page);

    // second packet!
    if (!start_page(f))                              return FALSE;

    if (!start_packet(f))                            return FALSE;
    do {
        len = next_segment(f);
        skip(f, len);
        f->bytes_in_seg = 0;
    } while (len);

    // third packet!
    if (!start_packet(f))                            return FALSE;

#ifndef STB_VORBIS_NO_PUSHDATA_API
    if (IS_PUSH_MODE(f)) {
        if (!is_whole_packet_present(f, TRUE)) {
            // convert error in ogg header to write type
            if (f->error == VORBIS_invalid_stream)
                f->error = VORBIS_invalid_setup;
            return FALSE;
        }
    }
#endif

    crc32_init(); // always init it, to avoid multithread race conditions

    if (get8_packet(f) != VORBIS_packet_setup)       return error(f, VORBIS_invalid_setup);
    for (i = 0; i < 6; ++i) header[i] = get8_packet(f);
    if (!vorbis_validate(header))                    return error(f, VORBIS_invalid_setup);

    // codebooks

    f->codebook_count = get_bits(f, 8) + 1;
    f->codebooks = (Codebook *)setup_malloc(f, sizeof(*f->codebooks) * f->codebook_count);
    if (f->codebooks == NULL)                        return error(f, VORBIS_outofmem);
    memset(f->codebooks, 0, sizeof(*f->codebooks) * f->codebook_count);
    for (i = 0; i < f->codebook_count; ++i) {
        uint32 *values;
        int ordered, sorted_count;
        int total = 0;
        uint8 *lengths;
        Codebook *c = f->codebooks + i;
        CHECK(f);
        x = get_bits(f, 8); if (x != 0x42)            return error(f, VORBIS_invalid_setup);
        x = get_bits(f, 8); if (x != 0x43)            return error(f, VORBIS_invalid_setup);
        x = get_bits(f, 8); if (x != 0x56)            return error(f, VORBIS_invalid_setup);
        x = get_bits(f, 8);
        c->dimensions = (get_bits(f, 8) << 8) + x;
        x = get_bits(f, 8);
        y = get_bits(f, 8);
        c->entries = (get_bits(f, 8) << 16) + (y << 8) + x;
        ordered = get_bits(f, 1);
        c->sparse = ordered ? 0 : get_bits(f, 1);

        if (c->dimensions == 0 && c->entries != 0)    return error(f, VORBIS_invalid_setup);

        if (c->sparse)
            lengths = (uint8 *)setup_temp_malloc(f, c->entries);
        else
            lengths = c->codeword_lengths = (uint8 *)setup_malloc(f, c->entries);

        if (!lengths) return error(f, VORBIS_outofmem);

        if (ordered) {
            int current_entry = 0;
            int current_length = get_bits(f, 5) + 1;
            while (current_entry < c->entries) {
                int limit = c->entries - current_entry;
                int n = get_bits(f, ilog(limit));
                if (current_entry + n >(int) c->entries) { return error(f, VORBIS_invalid_setup); }
                memset(lengths + current_entry, current_length, n);
                current_entry += n;
                ++current_length;
            }
        }
        else {
            for (j = 0; j < c->entries; ++j) {
                int present = c->sparse ? get_bits(f, 1) : 1;
                if (present) {
                    lengths[j] = get_bits(f, 5) + 1;
                    ++total;
                    if (lengths[j] == 32)
                        return error(f, VORBIS_invalid_setup);
                }
                else {
                    lengths[j] = NO_CODE;
                }
            }
        }

        if (c->sparse && total >= c->entries >> 2) {
            // convert sparse items to non-sparse!
            if (c->entries > (int)f->setup_temp_memory_required)
                f->setup_temp_memory_required = c->entries;

            c->codeword_lengths = (uint8 *)setup_malloc(f, c->entries);
            if (c->codeword_lengths == NULL) return error(f, VORBIS_outofmem);
            memcpy(c->codeword_lengths, lengths, c->entries);
            setup_temp_free(f, lengths, c->entries); // note this is only safe if there have been no intervening temp mallocs!
            lengths = c->codeword_lengths;
            c->sparse = 0;
        }

        // compute the size of the sorted tables
        if (c->sparse) {
            sorted_count = total;
        }
        else {
            sorted_count = 0;
#ifndef STB_VORBIS_NO_HUFFMAN_BINARY_SEARCH
            for (j = 0; j < c->entries; ++j)
                if (lengths[j] > STB_VORBIS_FAST_HUFFMAN_LENGTH && lengths[j] != NO_CODE)
                    ++sorted_count;
#endif
        }

        c->sorted_entries = sorted_count;
        values = NULL;

        CHECK(f);
        if (!c->sparse) {
            c->codewords = (uint32 *)setup_malloc(f, sizeof(c->codewords[0]) * c->entries);
            if (!c->codewords)                  return error(f, VORBIS_outofmem);
        }
        else {
            unsigned int size;
            if (c->sorted_entries) {
                c->codeword_lengths = (uint8 *)setup_malloc(f, c->sorted_entries);
                if (!c->codeword_lengths)           return error(f, VORBIS_outofmem);
                c->codewords = (uint32 *)setup_temp_malloc(f, sizeof(*c->codewords) * c->sorted_entries);
                if (!c->codewords)                  return error(f, VORBIS_outofmem);
                values = (uint32 *)setup_temp_malloc(f, sizeof(*values) * c->sorted_entries);
                if (!values)                        return error(f, VORBIS_outofmem);
            }
            size = c->entries + (sizeof(*c->codewords) + sizeof(*values)) * c->sorted_entries;
            if (size > f->setup_temp_memory_required)
                f->setup_temp_memory_required = size;
        }

        if (!compute_codewords(c, lengths, c->entries, values)) {
            if (c->sparse) setup_temp_free(f, values, 0);
            return error(f, VORBIS_invalid_setup);
        }

        if (c->sorted_entries) {
            // allocate an extra slot for sentinels
            c->sorted_codewords = (uint32 *)setup_malloc(f, sizeof(*c->sorted_codewords) * (c->sorted_entries + 1));
            if (c->sorted_codewords == NULL) return error(f, VORBIS_outofmem);
            // allocate an extra slot at the front so that c->sorted_values[-1] is defined
            // so that we can catch that case without an extra if
            c->sorted_values = (int   *)setup_malloc(f, sizeof(*c->sorted_values) * (c->sorted_entries + 1));
            if (c->sorted_values == NULL) return error(f, VORBIS_outofmem);
            ++c->sorted_values;
            c->sorted_values[-1] = -1;
            compute_sorted_huffman(c, lengths, values);
        }

        if (c->sparse) {
            setup_temp_free(f, values, sizeof(*values)*c->sorted_entries);
            setup_temp_free(f, c->codewords, sizeof(*c->codewords)*c->sorted_entries);
            setup_temp_free(f, lengths, c->entries);
            c->codewords = NULL;
        }

        compute_accelerated_huffman(c);

        CHECK(f);
        c->lookup_type = get_bits(f, 4);
        if (c->lookup_type > 2) return error(f, VORBIS_invalid_setup);
        if (c->lookup_type > 0) {
            uint16 *mults;
            c->minimum_value = float32_unpack(get_bits(f, 32));
            c->delta_value = float32_unpack(get_bits(f, 32));
            c->value_bits = get_bits(f, 4) + 1;
            c->sequence_p = get_bits(f, 1);
            if (c->lookup_type == 1) {
                c->lookup_values = lookup1_values(c->entries, c->dimensions);
            }
            else {
                c->lookup_values = c->entries * c->dimensions;
            }
            if (c->lookup_values == 0) return error(f, VORBIS_invalid_setup);
            mults = (uint16 *)setup_temp_malloc(f, sizeof(mults[0]) * c->lookup_values);
            if (mults == NULL) return error(f, VORBIS_outofmem);
            for (j = 0; j < (int)c->lookup_values; ++j) {
                int q = get_bits(f, c->value_bits);
                if (q == EOP) { setup_temp_free(f, mults, sizeof(mults[0])*c->lookup_values); return error(f, VORBIS_invalid_setup); }
                mults[j] = q;
            }

#ifndef STB_VORBIS_DIVIDES_IN_CODEBOOK
            if (c->lookup_type == 1) {
                int len, sparse = c->sparse;
                float last = 0;
                // pre-expand the lookup1-style multiplicands, to avoid a divide in the inner loop
                if (sparse) {
                    if (c->sorted_entries == 0) goto skip;
                    c->multiplicands = (codetype *)setup_malloc(f, sizeof(c->multiplicands[0]) * c->sorted_entries * c->dimensions);
                }
                else
                    c->multiplicands = (codetype *)setup_malloc(f, sizeof(c->multiplicands[0]) * c->entries        * c->dimensions);
                if (c->multiplicands == NULL) { setup_temp_free(f, mults, sizeof(mults[0])*c->lookup_values); return error(f, VORBIS_outofmem); }
                len = sparse ? c->sorted_entries : c->entries;
                for (j = 0; j < len; ++j) {
                    unsigned int z = sparse ? c->sorted_values[j] : j;
                    unsigned int div = 1;
                    for (k = 0; k < c->dimensions; ++k) {
                        int off = (z / div) % c->lookup_values;
                        float val = mults[off];
                        val = mults[off] * c->delta_value + c->minimum_value + last;
                        c->multiplicands[j*c->dimensions + k] = val;
                        if (c->sequence_p)
                            last = val;
                        if (k + 1 < c->dimensions) {
                            if (div > UINT_MAX / (unsigned int)c->lookup_values) {
                                setup_temp_free(f, mults, sizeof(mults[0])*c->lookup_values);
                                return error(f, VORBIS_invalid_setup);
                            }
                            div *= c->lookup_values;
                        }
                    }
                }
                setup_temp_free(f, mults, sizeof(mults[0])*c->lookup_values);
                c->lookup_type = 2;
            }
            else
#endif
            {
                float last = 0;
                CHECK(f);
                c->multiplicands = (codetype *)setup_malloc(f, sizeof(c->multiplicands[0]) * c->lookup_values);
                if (c->multiplicands == NULL) { setup_temp_free(f, mults, sizeof(mults[0])*c->lookup_values); return error(f, VORBIS_outofmem); }
                for (j = 0; j < (int)c->lookup_values; ++j) {
                    float val = mults[j] * c->delta_value + c->minimum_value + last;
                    c->multiplicands[j] = val;
                    if (c->sequence_p)
                        last = val;
                }
                setup_temp_free(f, mults, sizeof(mults[0])*c->lookup_values);
            }
#ifndef STB_VORBIS_DIVIDES_IN_CODEBOOK
            skip : ;
#endif

                   CHECK(f);
        }
        CHECK(f);
    }

    // time domain transfers (notused)

    x = get_bits(f, 6) + 1;
    for (i = 0; i < x; ++i) {
        uint32 z = get_bits(f, 16);
        if (z != 0) return error(f, VORBIS_invalid_setup);
    }

    // Floors
    f->floor_count = get_bits(f, 6) + 1;
    f->floor_config = (Floor *)setup_malloc(f, f->floor_count * sizeof(*f->floor_config));
    if (f->floor_config == NULL) return error(f, VORBIS_outofmem);
    for (i = 0; i < f->floor_count; ++i) {
        f->floor_types[i] = get_bits(f, 16);
        if (f->floor_types[i] > 1) return error(f, VORBIS_invalid_setup);
        if (f->floor_types[i] == 0) {
            Floor0 *g = &f->floor_config[i].floor0;
            g->order = get_bits(f, 8);
            g->rate = get_bits(f, 16);
            g->bark_map_size = get_bits(f, 16);
            g->amplitude_bits = get_bits(f, 6);
            g->amplitude_offset = get_bits(f, 8);
            g->number_of_books = get_bits(f, 4) + 1;
            for (j = 0; j < g->number_of_books; ++j)
                g->book_list[j] = get_bits(f, 8);
            return error(f, VORBIS_feature_not_supported);
        }
        else {
            Point p[31 * 8 + 2];
            Floor1 *g = &f->floor_config[i].floor1;
            int max_class = -1;
            g->partitions = get_bits(f, 5);
            for (j = 0; j < g->partitions; ++j) {
                g->partition_class_list[j] = get_bits(f, 4);
                if (g->partition_class_list[j] > max_class)
                    max_class = g->partition_class_list[j];
            }
            for (j = 0; j <= max_class; ++j) {
                g->class_dimensions[j] = get_bits(f, 3) + 1;
                g->class_subclasses[j] = get_bits(f, 2);
                if (g->class_subclasses[j]) {
                    g->class_masterbooks[j] = get_bits(f, 8);
                    if (g->class_masterbooks[j] >= f->codebook_count) return error(f, VORBIS_invalid_setup);
                }
                for (k = 0; k < 1 << g->class_subclasses[j]; ++k) {
                    g->subclass_books[j][k] = get_bits(f, 8) - 1;
                    if (g->subclass_books[j][k] >= f->codebook_count) return error(f, VORBIS_invalid_setup);
                }
            }
            g->floor1_multiplier = get_bits(f, 2) + 1;
            g->rangebits = get_bits(f, 4);
            g->Xlist[0] = 0;
            g->Xlist[1] = 1 << g->rangebits;
            g->values = 2;
            for (j = 0; j < g->partitions; ++j) {
                int c = g->partition_class_list[j];
                for (k = 0; k < g->class_dimensions[c]; ++k) {
                    g->Xlist[g->values] = get_bits(f, g->rangebits);
                    ++g->values;
                }
            }
            // precompute the sorting
            for (j = 0; j < g->values; ++j) {
                p[j].x = g->Xlist[j];
                p[j].y = j;
            }
            qsort(p, g->values, sizeof(p[0]), point_compare);
            for (j = 0; j < g->values; ++j)
                g->sorted_order[j] = (uint8)p[j].y;
            // precompute the neighbors
            for (j = 2; j < g->values; ++j) {
                int low, hi;
                neighbors(g->Xlist, j, &low, &hi);
                g->neighbors[j][0] = low;
                g->neighbors[j][1] = hi;
            }

            if (g->values > longest_floorlist)
                longest_floorlist = g->values;
        }
    }

    // Residue
    f->residue_count = get_bits(f, 6) + 1;
    f->residue_config = (Residue *)setup_malloc(f, f->residue_count * sizeof(f->residue_config[0]));
    if (f->residue_config == NULL) return error(f, VORBIS_outofmem);
    memset(f->residue_config, 0, f->residue_count * sizeof(f->residue_config[0]));
    for (i = 0; i < f->residue_count; ++i) {
        uint8 residue_cascade[64];
        Residue *r = f->residue_config + i;
        f->residue_types[i] = get_bits(f, 16);
        if (f->residue_types[i] > 2) return error(f, VORBIS_invalid_setup);
        r->begin = get_bits(f, 24);
        r->end = get_bits(f, 24);
        if (r->end < r->begin) return error(f, VORBIS_invalid_setup);
        r->part_size = get_bits(f, 24) + 1;
        r->classifications = get_bits(f, 6) + 1;
        r->classbook = get_bits(f, 8);
        if (r->classbook >= f->codebook_count) return error(f, VORBIS_invalid_setup);
        for (j = 0; j < r->classifications; ++j) {
            uint8 high_bits = 0;
            uint8 low_bits = get_bits(f, 3);
            if (get_bits(f, 1))
                high_bits = get_bits(f, 5);
            residue_cascade[j] = high_bits * 8 + low_bits;
        }
        r->residue_books = (short(*)[8]) setup_malloc(f, sizeof(r->residue_books[0]) * r->classifications);
        if (r->residue_books == NULL) return error(f, VORBIS_outofmem);
        for (j = 0; j < r->classifications; ++j) {
            for (k = 0; k < 8; ++k) {
                if (residue_cascade[j] & (1 << k)) {
                    r->residue_books[j][k] = get_bits(f, 8);
                    if (r->residue_books[j][k] >= f->codebook_count) return error(f, VORBIS_invalid_setup);
                }
                else {
                    r->residue_books[j][k] = -1;
                }
            }
        }
        // precompute the classifications[] array to avoid inner-loop mod/divide
        // call it 'classdata' since we already have r->classifications
        r->classdata = (uint8 **)setup_malloc(f, sizeof(*r->classdata) * f->codebooks[r->classbook].entries);
        if (!r->classdata) return error(f, VORBIS_outofmem);
        memset(r->classdata, 0, sizeof(*r->classdata) * f->codebooks[r->classbook].entries);
        for (j = 0; j < f->codebooks[r->classbook].entries; ++j) {
            int classwords = f->codebooks[r->classbook].dimensions;
            int temp = j;
            r->classdata[j] = (uint8 *)setup_malloc(f, sizeof(r->classdata[j][0]) * classwords);
            if (r->classdata[j] == NULL) return error(f, VORBIS_outofmem);
            for (k = classwords - 1; k >= 0; --k) {
                r->classdata[j][k] = temp % r->classifications;
                temp /= r->classifications;
            }
        }
    }

    f->mapping_count = get_bits(f, 6) + 1;
    f->mapping = (Mapping *)setup_malloc(f, f->mapping_count * sizeof(*f->mapping));
    if (f->mapping == NULL) return error(f, VORBIS_outofmem);
    memset(f->mapping, 0, f->mapping_count * sizeof(*f->mapping));
    for (i = 0; i < f->mapping_count; ++i) {
        Mapping *m = f->mapping + i;
        int mapping_type = get_bits(f, 16);
        if (mapping_type != 0) return error(f, VORBIS_invalid_setup);
        m->chan = (MappingChannel *)setup_malloc(f, f->channels * sizeof(*m->chan));
        if (m->chan == NULL) return error(f, VORBIS_outofmem);
        if (get_bits(f, 1))
            m->submaps = get_bits(f, 4) + 1;
        else
            m->submaps = 1;
        if (m->submaps > max_submaps)
            max_submaps = m->submaps;
        if (get_bits(f, 1)) {
            m->coupling_steps = get_bits(f, 8) + 1;
            for (k = 0; k < m->coupling_steps; ++k) {
                m->chan[k].magnitude = get_bits(f, ilog(f->channels - 1));
                m->chan[k].angle = get_bits(f, ilog(f->channels - 1));
                if (m->chan[k].magnitude >= f->channels)        return error(f, VORBIS_invalid_setup);
                if (m->chan[k].angle >= f->channels)        return error(f, VORBIS_invalid_setup);
                if (m->chan[k].magnitude == m->chan[k].angle)   return error(f, VORBIS_invalid_setup);
            }
        }
        else
            m->coupling_steps = 0;

        // reserved field
        if (get_bits(f, 2)) return error(f, VORBIS_invalid_setup);
        if (m->submaps > 1) {
            for (j = 0; j < f->channels; ++j) {
                m->chan[j].mux = get_bits(f, 4);
                if (m->chan[j].mux >= m->submaps)                return error(f, VORBIS_invalid_setup);
            }
        }
        else
            // @SPECIFICATION: this case is missing from the spec
            for (j = 0; j < f->channels; ++j)
                m->chan[j].mux = 0;

        for (j = 0; j < m->submaps; ++j) {
            get_bits(f, 8); // discard
            m->submap_floor[j] = get_bits(f, 8);
            m->submap_residue[j] = get_bits(f, 8);
            if (m->submap_floor[j] >= f->floor_count)      return error(f, VORBIS_invalid_setup);
            if (m->submap_residue[j] >= f->residue_count)  return error(f, VORBIS_invalid_setup);
        }
    }

    // Modes
    f->mode_count = get_bits(f, 6) + 1;
    for (i = 0; i < f->mode_count; ++i) {
        Mode *m = f->mode_config + i;
        m->blockflag = get_bits(f, 1);
        m->windowtype = get_bits(f, 16);
        m->transformtype = get_bits(f, 16);
        m->mapping = get_bits(f, 8);
        if (m->windowtype != 0)                 return error(f, VORBIS_invalid_setup);
        if (m->transformtype != 0)              return error(f, VORBIS_invalid_setup);
        if (m->mapping >= f->mapping_count)     return error(f, VORBIS_invalid_setup);
    }

    flush_packet(f);

    f->previous_length = 0;

    for (i = 0; i < f->channels; ++i) {
        f->channel_buffers[i] = (float *)setup_malloc(f, sizeof(float) * f->blocksize_1);
        f->previous_window[i] = (float *)setup_malloc(f, sizeof(float) * f->blocksize_1 / 2);
        f->finalY[i] = (int16 *)setup_malloc(f, sizeof(int16) * longest_floorlist);
        if (f->channel_buffers[i] == NULL || f->previous_window[i] == NULL || f->finalY[i] == NULL) return error(f, VORBIS_outofmem);
#ifdef STB_VORBIS_NO_DEFER_FLOOR
        f->floor_buffers[i] = (float *)setup_malloc(f, sizeof(float) * f->blocksize_1 / 2);
        if (f->floor_buffers[i] == NULL) return error(f, VORBIS_outofmem);
#endif
    }

    if (!init_blocksize(f, 0, f->blocksize_0)) return FALSE;
    if (!init_blocksize(f, 1, f->blocksize_1)) return FALSE;
    f->blocksize[0] = f->blocksize_0;
    f->blocksize[1] = f->blocksize_1;

#ifdef STB_VORBIS_DIVIDE_TABLE
    if (integer_divide_table[1][1] == 0)
        for (i = 0; i < DIVTAB_NUMER; ++i)
            for (j = 1; j < DIVTAB_DENOM; ++j)
                integer_divide_table[i][j] = i / j;
#endif

    // compute how much temporary memory is needed

    // 1.
    {
        uint32 imdct_mem = (f->blocksize_1 * sizeof(float) >> 1);
        uint32 classify_mem;
        int i, max_part_read = 0;
        for (i = 0; i < f->residue_count; ++i) {
            Residue *r = f->residue_config + i;
            int n_read = r->end - r->begin;
            int part_read = n_read / r->part_size;
            if (part_read > max_part_read)
                max_part_read = part_read;
        }
#ifndef STB_VORBIS_DIVIDES_IN_RESIDUE
        classify_mem = f->channels * (sizeof(void*) + max_part_read * sizeof(uint8 *));
#else
        classify_mem = f->channels * (sizeof(void*) + max_part_read * sizeof(int *));
#endif

        f->temp_memory_required = classify_mem;
        if (imdct_mem > f->temp_memory_required)
            f->temp_memory_required = imdct_mem;
    }

    f->first_decode = TRUE;

    if (f->alloc.alloc_buffer) {
        assert(f->temp_offset == f->alloc.alloc_buffer_length_in_bytes);
        // check if there's enough temp memory so we don't error later
        if (f->setup_offset + sizeof(*f) + f->temp_memory_required > (unsigned)f->temp_offset)
            return error(f, VORBIS_outofmem);
    }

    f->first_audio_page_offset = stb_vorbis_get_file_offset(f);

    return TRUE;
}

static void vorbis_deinit(stb_vorbis *p)
{
    int i, j;
    if (p->residue_config) {
        for (i = 0; i < p->residue_count; ++i) {
            Residue *r = p->residue_config + i;
            if (r->classdata) {
                for (j = 0; j < p->codebooks[r->classbook].entries; ++j)
                    setup_free(p, r->classdata[j]);
                setup_free(p, r->classdata);
            }
            setup_free(p, r->residue_books);
        }
    }

    if (p->codebooks) {
        CHECK(p);
        for (i = 0; i < p->codebook_count; ++i) {
            Codebook *c = p->codebooks + i;
            setup_free(p, c->codeword_lengths);
            setup_free(p, c->multiplicands);
            setup_free(p, c->codewords);
            setup_free(p, c->sorted_codewords);
            // c->sorted_values[-1] is the first entry in the array
            setup_free(p, c->sorted_values ? c->sorted_values - 1 : NULL);
        }
        setup_free(p, p->codebooks);
    }
    setup_free(p, p->floor_config);
    setup_free(p, p->residue_config);
    if (p->mapping) {
        for (i = 0; i < p->mapping_count; ++i)
            setup_free(p, p->mapping[i].chan);
        setup_free(p, p->mapping);
    }
    CHECK(p);
    for (i = 0; i < p->channels && i < STB_VORBIS_MAX_CHANNELS; ++i) {
        setup_free(p, p->channel_buffers[i]);
        setup_free(p, p->previous_window[i]);
#ifdef STB_VORBIS_NO_DEFER_FLOOR
        setup_free(p, p->floor_buffers[i]);
#endif
        setup_free(p, p->finalY[i]);
    }
    for (i = 0; i < 2; ++i) {
        setup_free(p, p->A[i]);
        setup_free(p, p->B[i]);
        setup_free(p, p->C[i]);
        setup_free(p, p->window[i]);
        setup_free(p, p->bit_reverse[i]);
    }
#ifndef STB_VORBIS_NO_STDIO
    if (p->close_on_free) fclose(p->f);
#endif
}

void stb_vorbis_close(stb_vorbis *p)
{
    if (p == NULL) return;
    vorbis_deinit(p);
    setup_free(p, p);
}

static void vorbis_init(stb_vorbis *p, const stb_vorbis_alloc *z)
{
    memset(p, 0, sizeof(*p)); // NULL out all malloc'd pointers to start
    if (z) {
        p->alloc = *z;
        p->alloc.alloc_buffer_length_in_bytes = (p->alloc.alloc_buffer_length_in_bytes + 3) & ~3;
        p->temp_offset = p->alloc.alloc_buffer_length_in_bytes;
    }
    p->eof = 0;
    p->error = VORBIS__no_error;
    p->stream = NULL;
    p->codebooks = NULL;
    p->page_crc_tests = -1;
#ifndef STB_VORBIS_NO_STDIO
    p->close_on_free = FALSE;
    p->f = NULL;
#endif
}

int stb_vorbis_get_sample_offset(stb_vorbis *f)
{
    if (f->current_loc_valid)
        return f->current_loc;
    else
        return -1;
}

stb_vorbis_info stb_vorbis_get_info(stb_vorbis *f)
{
    stb_vorbis_info d;
    d.channels = f->channels;
    d.sample_rate = f->sample_rate;
    d.setup_memory_required = f->setup_memory_required;
    d.setup_temp_memory_required = f->setup_temp_memory_required;
    d.temp_memory_required = f->temp_memory_required;
    d.max_frame_size = f->blocksize_1 >> 1;
    return d;
}

int stb_vorbis_get_error(stb_vorbis *f)
{
    int e = f->error;
    f->error = VORBIS__no_error;
    return e;
}

static stb_vorbis * vorbis_alloc(stb_vorbis *f)
{
    stb_vorbis *p = (stb_vorbis *)setup_malloc(f, sizeof(*p));
    return p;
}

#ifndef STB_VORBIS_NO_PUSHDATA_API

void stb_vorbis_flush_pushdata(stb_vorbis *f)
{
    f->previous_length = 0;
    f->page_crc_tests = 0;
    f->discard_samples_deferred = 0;
    f->current_loc_valid = FALSE;
    f->first_decode = FALSE;
    f->samples_output = 0;
    f->channel_buffer_start = 0;
    f->channel_buffer_end = 0;
}

static int vorbis_search_for_page_pushdata(vorb *f, uint8 *data, int data_len)
{
    int i, n;
    for (i = 0; i < f->page_crc_tests; ++i)
        f->scan[i].bytes_done = 0;

    // if we have room for more scans, search for them first, because
    // they may cause us to stop early if their header is incomplete
    if (f->page_crc_tests < STB_VORBIS_PUSHDATA_CRC_COUNT) {
        if (data_len < 4) return 0;
        data_len -= 3; // need to look for 4-byte sequence, so don't miss
                       // one that straddles a boundary
        for (i = 0; i < data_len; ++i) {
            if (data[i] == 0x4f) {
                if (0 == memcmp(data + i, ogg_page_header, 4)) {
                    int j, len;
                    uint32 crc;
                    // make sure we have the whole page header
                    if (i + 26 >= data_len || i + 27 + data[i + 26] >= data_len) {
                        // only read up to this page start, so hopefully we'll
                        // have the whole page header start next time
                        data_len = i;
                        break;
                    }
                    // ok, we have it all; compute the length of the page
                    len = 27 + data[i + 26];
                    for (j = 0; j < data[i + 26]; ++j)
                        len += data[i + 27 + j];
                    // scan everything up to the embedded crc (which we must 0)
                    crc = 0;
                    for (j = 0; j < 22; ++j)
                        crc = crc32_update(crc, data[i + j]);
                    // now process 4 0-bytes
                    for (; j < 26; ++j)
                        crc = crc32_update(crc, 0);
                    // len is the total number of bytes we need to scan
                    n = f->page_crc_tests++;
                    f->scan[n].bytes_left = len - j;
                    f->scan[n].crc_so_far = crc;
                    f->scan[n].goal_crc = data[i + 22] + (data[i + 23] << 8) + (data[i + 24] << 16) + (data[i + 25] << 24);
                    // if the last frame on a page is continued to the next, then
                    // we can't recover the sample_loc immediately
                    if (data[i + 27 + data[i + 26] - 1] == 255)
                        f->scan[n].sample_loc = ~0;
                    else
                        f->scan[n].sample_loc = data[i + 6] + (data[i + 7] << 8) + (data[i + 8] << 16) + (data[i + 9] << 24);
                    f->scan[n].bytes_done = i + j;
                    if (f->page_crc_tests == STB_VORBIS_PUSHDATA_CRC_COUNT)
                        break;
                    // keep going if we still have room for more
                }
            }
        }
    }

    for (i = 0; i < f->page_crc_tests;) {
        uint32 crc;
        int j;
        int n = f->scan[i].bytes_done;
        int m = f->scan[i].bytes_left;
        if (m > data_len - n) m = data_len - n;
        // m is the bytes to scan in the current chunk
        crc = f->scan[i].crc_so_far;
        for (j = 0; j < m; ++j)
            crc = crc32_update(crc, data[n + j]);
        f->scan[i].bytes_left -= m;
        f->scan[i].crc_so_far = crc;
        if (f->scan[i].bytes_left == 0) {
            // does it match?
            if (f->scan[i].crc_so_far == f->scan[i].goal_crc) {
                // Houston, we have page
                data_len = n + m; // consumption amount is wherever that scan ended
                f->page_crc_tests = -1; // drop out of page scan mode
                f->previous_length = 0; // decode-but-don't-output one frame
                f->next_seg = -1;       // start a new page
                f->current_loc = f->scan[i].sample_loc; // set the current sample location
                                                        // to the amount we'd have decoded had we decoded this page
                f->current_loc_valid = f->current_loc != ~0U;
                return data_len;
            }
            // delete entry
            f->scan[i] = f->scan[--f->page_crc_tests];
        }
        else {
            ++i;
        }
    }

    return data_len;
}

// return value: number of bytes we used
int stb_vorbis_decode_frame_pushdata(
    stb_vorbis *f,                   // the file we're decoding
    const uint8 *data, int data_len, // the memory available for decoding
    int *channels,                   // place to write number of float * buffers
    float ***output,                 // place to write float ** array of float * buffers
    int *samples                     // place to write number of output samples
    )
{
    int i;
    int len, right, left;

    if (!IS_PUSH_MODE(f)) return error(f, VORBIS_invalid_api_mixing);

    if (f->page_crc_tests >= 0) {
        *samples = 0;
        return vorbis_search_for_page_pushdata(f, (uint8 *)data, data_len);
    }

    f->stream = (uint8 *)data;
    f->stream_end = (uint8 *)data + data_len;
    f->error = VORBIS__no_error;

    // check that we have the entire packet in memory
    if (!is_whole_packet_present(f, FALSE)) {
        *samples = 0;
        return 0;
    }

    if (!vorbis_decode_packet(f, &len, &left, &right)) {
        // save the actual error we encountered
        enum STBVorbisError error = f->error;
        if (error == VORBIS_bad_packet_type) {
            // flush and resynch
            f->error = VORBIS__no_error;
            while (get8_packet(f) != EOP)
                if (f->eof) break;
            *samples = 0;
            return f->stream - data;
        }
        if (error == VORBIS_continued_packet_flag_invalid) {
            if (f->previous_length == 0) {
                // we may be resynching, in which case it's ok to hit one
                // of these; just discard the packet
                f->error = VORBIS__no_error;
                while (get8_packet(f) != EOP)
                    if (f->eof) break;
                *samples = 0;
                return f->stream - data;
            }
        }
        // if we get an error while parsing, what to do?
        // well, it DEFINITELY won't work to continue from where we are!
        stb_vorbis_flush_pushdata(f);
        // restore the error that actually made us bail
        f->error = error;
        *samples = 0;
        return 1;
    }

    // success!
    len = vorbis_finish_frame(f, len, left, right);
    for (i = 0; i < f->channels; ++i)
        f->outputs[i] = f->channel_buffers[i] + left;

    if (channels) *channels = f->channels;
    *samples = len;
    *output = f->outputs;
    return f->stream - data;
}

stb_vorbis *stb_vorbis_open_pushdata(
    const unsigned char *data, int data_len, // the memory available for decoding
    int *data_used,              // only defined if result is not NULL
    int *error, const stb_vorbis_alloc *alloc)
{
    stb_vorbis *f, p;
    vorbis_init(&p, alloc);
    p.stream = (uint8 *)data;
    p.stream_end = (uint8 *)data + data_len;
    p.push_mode = TRUE;
    if (!start_decoder(&p)) {
        if (p.eof)
            *error = VORBIS_need_more_data;
        else
            *error = p.error;
        return NULL;
    }
    f = vorbis_alloc(&p);
    if (f) {
        *f = p;
        *data_used = f->stream - data;
        *error = 0;
        return f;
    }
    else {
        vorbis_deinit(&p);
        return NULL;
    }
}
#endif // STB_VORBIS_NO_PUSHDATA_API

unsigned int stb_vorbis_get_file_offset(stb_vorbis *f)
{
#ifndef STB_VORBIS_NO_PUSHDATA_API
    if (f->push_mode) return 0;
#endif
    if (USE_MEMORY(f)) return f->stream - f->stream_start;
#ifndef STB_VORBIS_NO_STDIO
    return ftell(f->f) - f->f_start;
#endif
}

#ifndef STB_VORBIS_NO_PULLDATA_API
//
// DATA-PULLING API
//

static uint32 vorbis_find_page(stb_vorbis *f, uint32 *end, uint32 *last)
{
    for (;;) {
        int n;
        if (f->eof) return 0;
        n = get8(f);
        if (n == 0x4f) { // page header candidate
            unsigned int retry_loc = stb_vorbis_get_file_offset(f);
            int i;
            // check if we're off the end of a file_section stream
            if (retry_loc - 25 > f->stream_len)
                return 0;
            // check the rest of the header
            for (i = 1; i < 4; ++i)
                if (get8(f) != ogg_page_header[i])
                    break;
            if (f->eof) return 0;
            if (i == 4) {
                uint8 header[27];
                uint32 i, crc, goal, len;
                for (i = 0; i < 4; ++i)
                    header[i] = ogg_page_header[i];
                for (; i < 27; ++i)
                    header[i] = get8(f);
                if (f->eof) return 0;
                if (header[4] != 0) goto invalid;
                goal = header[22] + (header[23] << 8) + (header[24] << 16) + (header[25] << 24);
                for (i = 22; i < 26; ++i)
                    header[i] = 0;
                crc = 0;
                for (i = 0; i < 27; ++i)
                    crc = crc32_update(crc, header[i]);
                len = 0;
                for (i = 0; i < header[26]; ++i) {
                    int s = get8(f);
                    crc = crc32_update(crc, s);
                    len += s;
                }
                if (len && f->eof) return 0;
                for (i = 0; i < len; ++i)
                    crc = crc32_update(crc, get8(f));
                // finished parsing probable page
                if (crc == goal) {
                    // we could now check that it's either got the last
                    // page flag set, OR it's followed by the capture
                    // pattern, but I guess TECHNICALLY you could have
                    // a file with garbage between each ogg page and recover
                    // from it automatically? So even though that paranoia
                    // might decrease the chance of an invalid decode by
                    // another 2^32, not worth it since it would hose those
                    // invalid-but-useful files?
                    if (end)
                        *end = stb_vorbis_get_file_offset(f);
                    if (last) {
                        if (header[5] & 0x04)
                            *last = 1;
                        else
                            *last = 0;
                    }
                    set_file_offset(f, retry_loc - 1);
                    return 1;
                }
            }
        invalid:
            // not a valid page, so rewind and look for next one
            set_file_offset(f, retry_loc);
        }
    }
}


#define SAMPLE_unknown  0xffffffff

// seeking is implemented with a binary search, which narrows down the range to
// 64K, before using a linear search (because finding the synchronization
// pattern can be expensive, and the chance we'd find the end page again is
// relatively high for small ranges)
//
// two initial interpolation-style probes are used at the start of the search
// to try to bound either side of the binary search sensibly, while still
// working in O(log n) time if they fail.

static int get_seek_page_info(stb_vorbis *f, ProbedPage *z)
{
    uint8 header[27], lacing[255];
    int i, len;

    // record where the page starts
    z->page_start = stb_vorbis_get_file_offset(f);

    // parse the header
    getn(f, header, 27);
    if (header[0] != 'O' || header[1] != 'g' || header[2] != 'g' || header[3] != 'S')
        return 0;
    getn(f, lacing, header[26]);

    // determine the length of the payload
    len = 0;
    for (i = 0; i < header[26]; ++i)
        len += lacing[i];

    // this implies where the page ends
    z->page_end = z->page_start + 27 + header[26] + len;

    // read the last-decoded sample out of the data
    z->last_decoded_sample = header[6] + (header[7] << 8) + (header[8] << 16) + (header[9] << 24);

    // restore file state to where we were
    set_file_offset(f, z->page_start);
    return 1;
}

// rarely used function to seek back to the preceeding page while finding the
// start of a packet
static int go_to_page_before(stb_vorbis *f, unsigned int limit_offset)
{
    unsigned int previous_safe, end;

    // now we want to seek back 64K from the limit
    if (limit_offset >= 65536 && limit_offset - 65536 >= f->first_audio_page_offset)
        previous_safe = limit_offset - 65536;
    else
        previous_safe = f->first_audio_page_offset;

    set_file_offset(f, previous_safe);

    while (vorbis_find_page(f, &end, NULL)) {
        if (end >= limit_offset && stb_vorbis_get_file_offset(f) < limit_offset)
            return 1;
        set_file_offset(f, end);
    }

    return 0;
}

// implements the search logic for finding a page and starting decoding. if
// the function succeeds, current_loc_valid will be true and current_loc will
// be less than or equal to the provided sample number (the closer the
// better).
static int seek_to_sample_coarse(stb_vorbis *f, uint32 sample_number)
{
    ProbedPage left, right, mid;
    int i, start_seg_with_known_loc, end_pos, page_start;
    uint32 delta, stream_length, padding;
    double offset, bytes_per_sample;
    int probe = 0;

    // find the last page and validate the target sample
    stream_length = stb_vorbis_stream_length_in_samples(f);
    if (stream_length == 0)            return error(f, VORBIS_seek_without_length);
    if (sample_number > stream_length) return error(f, VORBIS_seek_invalid);

    // this is the maximum difference between the window-center (which is the
    // actual granule position value), and the right-start (which the spec
    // indicates should be the granule position (give or take one)).
    padding = ((f->blocksize_1 - f->blocksize_0) >> 2);
    if (sample_number < padding)
        sample_number = 0;
    else
        sample_number -= padding;

    left = f->p_first;
    while (left.last_decoded_sample == ~0U) {
        // (untested) the first page does not have a 'last_decoded_sample'
        set_file_offset(f, left.page_end);
        if (!get_seek_page_info(f, &left)) goto error;
    }

    right = f->p_last;
    assert(right.last_decoded_sample != ~0U);

    // starting from the start is handled differently
    if (sample_number <= left.last_decoded_sample) {
        stb_vorbis_seek_start(f);
        return 1;
    }

    while (left.page_end != right.page_start) {
        assert(left.page_end < right.page_start);
        // search range in bytes
        delta = right.page_start - left.page_end;
        if (delta <= 65536) {
            // there's only 64K left to search - handle it linearly
            set_file_offset(f, left.page_end);
        }
        else {
            if (probe < 2) {
                if (probe == 0) {
                    // first probe (interpolate)
                    double data_bytes = right.page_end - left.page_start;
                    bytes_per_sample = data_bytes / right.last_decoded_sample;
                    offset = left.page_start + bytes_per_sample * (sample_number - left.last_decoded_sample);
                }
                else {
                    // second probe (try to bound the other side)
                    double error = ((double)sample_number - mid.last_decoded_sample) * bytes_per_sample;
                    if (error >= 0 && error <  8000) error = 8000;
                    if (error <  0 && error > -8000) error = -8000;
                    offset += error * 2;
                }

                // ensure the offset is valid
                if (offset < left.page_end)
                    offset = left.page_end;
                if (offset > right.page_start - 65536)
                    offset = right.page_start - 65536;

                set_file_offset(f, (unsigned int)offset);
            }
            else {
                // binary search for large ranges (offset by 32K to ensure
                // we don't hit the right page)
                set_file_offset(f, left.page_end + (delta / 2) - 32768);
            }

            if (!vorbis_find_page(f, NULL, NULL)) goto error;
        }

        for (;;) {
            if (!get_seek_page_info(f, &mid)) goto error;
            if (mid.last_decoded_sample != ~0U) break;
            // (untested) no frames end on this page
            set_file_offset(f, mid.page_end);
            assert(mid.page_start < right.page_start);
        }

        // if we've just found the last page again then we're in a tricky file,
        // and we're close enough.
        if (mid.page_start == right.page_start)
            break;

        if (sample_number < mid.last_decoded_sample)
            right = mid;
        else
            left = mid;

        ++probe;
    }

    // seek back to start of the last packet
    page_start = left.page_start;
    set_file_offset(f, page_start);
    if (!start_page(f)) return error(f, VORBIS_seek_failed);
    end_pos = f->end_seg_with_known_loc;
    assert(end_pos >= 0);

    for (;;) {
        for (i = end_pos; i > 0; --i)
            if (f->segments[i - 1] != 255)
                break;

        start_seg_with_known_loc = i;

        if (start_seg_with_known_loc > 0 || !(f->page_flag & PAGEFLAG_continued_packet))
            break;

        // (untested) the final packet begins on an earlier page
        if (!go_to_page_before(f, page_start))
            goto error;

        page_start = stb_vorbis_get_file_offset(f);
        if (!start_page(f)) goto error;
        end_pos = f->segment_count - 1;
    }

    // prepare to start decoding
    f->current_loc_valid = FALSE;
    f->last_seg = FALSE;
    f->valid_bits = 0;
    f->packet_bytes = 0;
    f->bytes_in_seg = 0;
    f->previous_length = 0;
    f->next_seg = start_seg_with_known_loc;

    for (i = 0; i < start_seg_with_known_loc; i++)
        skip(f, f->segments[i]);

    // start decoding (optimizable - this frame is generally discarded)
    vorbis_pump_first_frame(f);
    return 1;

error:
    // try to restore the file to a valid state
    stb_vorbis_seek_start(f);
    return error(f, VORBIS_seek_failed);
}

// the same as vorbis_decode_initial, but without advancing
static int peek_decode_initial(vorb *f, int *p_left_start, int *p_left_end, int *p_right_start, int *p_right_end, int *mode)
{
    int bits_read, bytes_read;

    if (!vorbis_decode_initial(f, p_left_start, p_left_end, p_right_start, p_right_end, mode))
        return 0;

    // either 1 or 2 bytes were read, figure out which so we can rewind
    bits_read = 1 + ilog(f->mode_count - 1);
    if (f->mode_config[*mode].blockflag)
        bits_read += 2;
    bytes_read = (bits_read + 7) / 8;

    f->bytes_in_seg += bytes_read;
    f->packet_bytes -= bytes_read;
    skip(f, -bytes_read);
    if (f->next_seg == -1)
        f->next_seg = f->segment_count - 1;
    else
        f->next_seg--;
    f->valid_bits = 0;

    return 1;
}

int stb_vorbis_seek_frame(stb_vorbis *f, unsigned int sample_number)
{
    uint32 max_frame_samples;

    if (IS_PUSH_MODE(f)) return error(f, VORBIS_invalid_api_mixing);

    // fast page-level search
    if (!seek_to_sample_coarse(f, sample_number))
        return 0;

    assert(f->current_loc_valid);
    assert(f->current_loc <= sample_number);

    // linear search for the relevant packet
    max_frame_samples = (f->blocksize_1 * 3 - f->blocksize_0) >> 2;
    while (f->current_loc < sample_number) {
        int left_start, left_end, right_start, right_end, mode, frame_samples;
        if (!peek_decode_initial(f, &left_start, &left_end, &right_start, &right_end, &mode))
            return error(f, VORBIS_seek_failed);
        // calculate the number of samples returned by the next frame
        frame_samples = right_start - left_start;
        if (f->current_loc + frame_samples > sample_number) {
            return 1; // the next frame will contain the sample
        }
        else if (f->current_loc + frame_samples + max_frame_samples > sample_number) {
            // there's a chance the frame after this could contain the sample
            vorbis_pump_first_frame(f);
        }
        else {
            // this frame is too early to be relevant
            f->current_loc += frame_samples;
            f->previous_length = 0;
            maybe_start_packet(f);
            flush_packet(f);
        }
    }
    // the next frame will start with the sample
    assert(f->current_loc == sample_number);
    return 1;
}

int stb_vorbis_seek(stb_vorbis *f, unsigned int sample_number)
{
    if (!stb_vorbis_seek_frame(f, sample_number))
        return 0;

    if (sample_number != f->current_loc) {
        int n;
        uint32 frame_start = f->current_loc;
        stb_vorbis_get_frame_float(f, &n, NULL);
        assert(sample_number > frame_start);
        assert(f->channel_buffer_start + (int)(sample_number - frame_start) <= f->channel_buffer_end);
        f->channel_buffer_start += (sample_number - frame_start);
    }

    return 1;
}

void stb_vorbis_seek_start(stb_vorbis *f)
{
    if (IS_PUSH_MODE(f)) { error(f, VORBIS_invalid_api_mixing); return; }
    set_file_offset(f, f->first_audio_page_offset);
    f->previous_length = 0;
    f->first_decode = TRUE;
    f->next_seg = -1;
    vorbis_pump_first_frame(f);
}

unsigned int stb_vorbis_stream_length_in_samples(stb_vorbis *f)
{
    unsigned int restore_offset, previous_safe;
    unsigned int end, last_page_loc;

    if (IS_PUSH_MODE(f)) return error(f, VORBIS_invalid_api_mixing);
    if (!f->total_samples) {
        unsigned int last;
        uint32 lo, hi;
        char header[6];

        // first, store the current decode position so we can restore it
        restore_offset = stb_vorbis_get_file_offset(f);

        // now we want to seek back 64K from the end (the last page must
        // be at most a little less than 64K, but let's allow a little slop)
        if (f->stream_len >= 65536 && f->stream_len - 65536 >= f->first_audio_page_offset)
            previous_safe = f->stream_len - 65536;
        else
            previous_safe = f->first_audio_page_offset;

        set_file_offset(f, previous_safe);
        // previous_safe is now our candidate 'earliest known place that seeking
        // to will lead to the final page'

        if (!vorbis_find_page(f, &end, &last)) {
            // if we can't find a page, we're hosed!
            f->error = VORBIS_cant_find_last_page;
            f->total_samples = 0xffffffff;
            goto done;
        }

        // check if there are more pages
        last_page_loc = stb_vorbis_get_file_offset(f);

        // stop when the last_page flag is set, not when we reach eof;
        // this allows us to stop short of a 'file_section' end without
        // explicitly checking the length of the section
        while (!last) {
            set_file_offset(f, end);
            if (!vorbis_find_page(f, &end, &last)) {
                // the last page we found didn't have the 'last page' flag
                // set. whoops!
                break;
            }
            previous_safe = last_page_loc + 1;
            last_page_loc = stb_vorbis_get_file_offset(f);
        }

        set_file_offset(f, last_page_loc);

        // parse the header
        getn(f, (unsigned char *)header, 6);
        // extract the absolute granule position
        lo = get32(f);
        hi = get32(f);
        if (lo == 0xffffffff && hi == 0xffffffff) {
            f->error = VORBIS_cant_find_last_page;
            f->total_samples = SAMPLE_unknown;
            goto done;
        }
        if (hi)
            lo = 0xfffffffe; // saturate
        f->total_samples = lo;

        f->p_last.page_start = last_page_loc;
        f->p_last.page_end = end;
        f->p_last.last_decoded_sample = lo;

    done:
        set_file_offset(f, restore_offset);
    }
    return f->total_samples == SAMPLE_unknown ? 0 : f->total_samples;
}

float stb_vorbis_stream_length_in_seconds(stb_vorbis *f)
{
    return stb_vorbis_stream_length_in_samples(f) / (float)f->sample_rate;
}



int stb_vorbis_get_frame_float(stb_vorbis *f, int *channels, float ***output)
{
    int len, right, left, i;
    if (IS_PUSH_MODE(f)) return error(f, VORBIS_invalid_api_mixing);

    if (!vorbis_decode_packet(f, &len, &left, &right)) {
        f->channel_buffer_start = f->channel_buffer_end = 0;
        return 0;
    }

    len = vorbis_finish_frame(f, len, left, right);
    for (i = 0; i < f->channels; ++i)
        f->outputs[i] = f->channel_buffers[i] + left;

    f->channel_buffer_start = left;
    f->channel_buffer_end = left + len;

    if (channels) *channels = f->channels;
    if (output)   *output = f->outputs;
    return len;
}

#ifndef STB_VORBIS_NO_STDIO

stb_vorbis * stb_vorbis_open_file_section(FILE *file, int close_on_free, int *error, const stb_vorbis_alloc *alloc, unsigned int length)
{
    stb_vorbis *f, p;
    vorbis_init(&p, alloc);
    p.f = file;
    p.f_start = ftell(file);
    p.stream_len = length;
    p.close_on_free = close_on_free;
    if (start_decoder(&p)) {
        f = vorbis_alloc(&p);
        if (f) {
            *f = p;
            vorbis_pump_first_frame(f);
            return f;
        }
    }
    if (error) *error = p.error;
    vorbis_deinit(&p);
    return NULL;
}

stb_vorbis * stb_vorbis_open_file(FILE *file, int close_on_free, int *error, const stb_vorbis_alloc *alloc)
{
    unsigned int len, start;
    start = ftell(file);
    fseek(file, 0, SEEK_END);
    len = ftell(file) - start;
    fseek(file, start, SEEK_SET);
    return stb_vorbis_open_file_section(file, close_on_free, error, alloc, len);
}

stb_vorbis * stb_vorbis_open_filename(const char *filename, int *error, const stb_vorbis_alloc *alloc)
{
    FILE *f = NULL;
    
    errno_t err = fopen_s(&f, filename, "rb");
    if (f && err == 0) {
        return stb_vorbis_open_file(f, TRUE, error, alloc);
    }
    else {
        if (f) {
            fclose(f);
        }
    }
    if (error) *error = VORBIS_file_open_failure;
    return NULL;
}
#endif // STB_VORBIS_NO_STDIO

stb_vorbis * stb_vorbis_open_memory(const unsigned char *data, int len, int *error, const stb_vorbis_alloc *alloc)
{
    stb_vorbis *f, p;
    if (data == NULL) return NULL;
    vorbis_init(&p, alloc);
    p.stream = (uint8 *)data;
    p.stream_end = (uint8 *)data + len;
    p.stream_start = (uint8 *)p.stream;
    p.stream_len = len;
    p.push_mode = FALSE;
    if (start_decoder(&p)) {
        f = vorbis_alloc(&p);
        if (f) {
            *f = p;
            vorbis_pump_first_frame(f);
            return f;
        }
    }
    if (error) *error = p.error;
    vorbis_deinit(&p);
    return NULL;
}

#ifndef STB_VORBIS_NO_INTEGER_CONVERSION
#define PLAYBACK_MONO     1
#define PLAYBACK_LEFT     2
#define PLAYBACK_RIGHT    4

#define L  (PLAYBACK_LEFT  | PLAYBACK_MONO)
#define C  (PLAYBACK_LEFT  | PLAYBACK_RIGHT | PLAYBACK_MONO)
#define R  (PLAYBACK_RIGHT | PLAYBACK_MONO)

static int8 channel_position[7][6] =
{
    { 0 },
    { C },
    { L, R },
    { L, C, R },
    { L, R, L, R },
    { L, C, R, L, R },
    { L, C, R, L, R, C },
};


#ifndef STB_VORBIS_NO_FAST_SCALED_FLOAT
typedef union {
    float f;
    int i;
} float_conv;
typedef char stb_vorbis_float_size_test[sizeof(float) == 4 && sizeof(int) == 4];
#define FASTDEF(x) float_conv x
// add (1<<23) to convert to int, then divide by 2^SHIFT, then add 0.5/2^SHIFT to round
#define MAGIC(SHIFT) (1.5f * (1 << (23-SHIFT)) + 0.5f/(1 << SHIFT))
#define ADDEND(SHIFT) (((150-SHIFT) << 23) + (1 << 22))
#define FAST_SCALED_FLOAT_TO_INT(temp,x,s) (temp.f = (x) + MAGIC(s), temp.i - ADDEND(s))
#define check_endianness()  
#else
#define FAST_SCALED_FLOAT_TO_INT(temp,x,s) ((int) ((x) * (1 << (s))))
#define check_endianness()
#define FASTDEF(x)
#endif

static void copy_samples(short *dest, float *src, int len)
{
    int i;
    check_endianness();
    for (i = 0; i < len; ++i) {
        FASTDEF(temp);
        int v = FAST_SCALED_FLOAT_TO_INT(temp, src[i], 15);
        if ((unsigned int)(v + 32768) > 65535)
            v = v < 0 ? -32768 : 32767;
        dest[i] = v;
    }
}

static void compute_samples(int mask, short *output, int num_c, float **data, int d_offset, int len)
{
#define BUFFER_SIZE  32
    float buffer[BUFFER_SIZE];
    int i, j, o, n = BUFFER_SIZE;
    check_endianness();
    for (o = 0; o < len; o += BUFFER_SIZE) {
        memset(buffer, 0, sizeof(buffer));
        if (o + n > len) n = len - o;
        for (j = 0; j < num_c; ++j) {
            if (channel_position[num_c][j] & mask) {
                for (i = 0; i < n; ++i)
                    buffer[i] += data[j][d_offset + o + i];
            }
        }
        for (i = 0; i < n; ++i) {
            FASTDEF(temp);
            int v = FAST_SCALED_FLOAT_TO_INT(temp, buffer[i], 15);
            if ((unsigned int)(v + 32768) > 65535)
                v = v < 0 ? -32768 : 32767;
            output[o + i] = v;
        }
    }
}

static void compute_stereo_samples(short *output, int num_c, float **data, int d_offset, int len)
{
#define BUFFER_SIZE  32
    float buffer[BUFFER_SIZE];
    int i, j, o, n = BUFFER_SIZE >> 1;
    // o is the offset in the source data
    check_endianness();
    for (o = 0; o < len; o += BUFFER_SIZE >> 1) {
        // o2 is the offset in the output data
        int o2 = o << 1;
        memset(buffer, 0, sizeof(buffer));
        if (o + n > len) n = len - o;
        for (j = 0; j < num_c; ++j) {
            int m = channel_position[num_c][j] & (PLAYBACK_LEFT | PLAYBACK_RIGHT);
            if (m == (PLAYBACK_LEFT | PLAYBACK_RIGHT)) {
                for (i = 0; i < n; ++i) {
                    buffer[i * 2 + 0] += data[j][d_offset + o + i];
                    buffer[i * 2 + 1] += data[j][d_offset + o + i];
                }
            }
            else if (m == PLAYBACK_LEFT) {
                for (i = 0; i < n; ++i) {
                    buffer[i * 2 + 0] += data[j][d_offset + o + i];
                }
            }
            else if (m == PLAYBACK_RIGHT) {
                for (i = 0; i < n; ++i) {
                    buffer[i * 2 + 1] += data[j][d_offset + o + i];
                }
            }
        }
        for (i = 0; i < (n << 1); ++i) {
            FASTDEF(temp);
            int v = FAST_SCALED_FLOAT_TO_INT(temp, buffer[i], 15);
            if ((unsigned int)(v + 32768) > 65535)
                v = v < 0 ? -32768 : 32767;
            output[o2 + i] = v;
        }
    }
}

static void convert_samples_short(int buf_c, short **buffer, int b_offset, int data_c, float **data, int d_offset, int samples)
{
    int i;
    if (buf_c != data_c && buf_c <= 2 && data_c <= 6) {
        static int channel_selector[3][2] = { { 0 },{ PLAYBACK_MONO },{ PLAYBACK_LEFT, PLAYBACK_RIGHT } };
        for (i = 0; i < buf_c; ++i)
            compute_samples(channel_selector[buf_c][i], buffer[i] + b_offset, data_c, data, d_offset, samples);
    }
    else {
        int limit = buf_c < data_c ? buf_c : data_c;
        for (i = 0; i < limit; ++i)
            copy_samples(buffer[i] + b_offset, data[i] + d_offset, samples);
        for (; i < buf_c; ++i)
            memset(buffer[i] + b_offset, 0, sizeof(short) * samples);
    }
}

int stb_vorbis_get_frame_short(stb_vorbis *f, int num_c, short **buffer, int num_samples)
{
    float **output;
    int len = stb_vorbis_get_frame_float(f, NULL, &output);
    if (len > num_samples) len = num_samples;
    if (len)
        convert_samples_short(num_c, buffer, 0, f->channels, output, 0, len);
    return len;
}

static void convert_channels_short_interleaved(int buf_c, short *buffer, int data_c, float **data, int d_offset, int len)
{
    int i;
    check_endianness();
    if (buf_c != data_c && buf_c <= 2 && data_c <= 6) {
        assert(buf_c == 2);
        for (i = 0; i < buf_c; ++i)
            compute_stereo_samples(buffer, data_c, data, d_offset, len);
    }
    else {
        int limit = buf_c < data_c ? buf_c : data_c;
        int j;
        for (j = 0; j < len; ++j) {
            for (i = 0; i < limit; ++i) {
                FASTDEF(temp);
                float f = data[i][d_offset + j];
                int v = FAST_SCALED_FLOAT_TO_INT(temp, f, 15);//data[i][d_offset+j],15);
                if ((unsigned int)(v + 32768) > 65535)
                    v = v < 0 ? -32768 : 32767;
                *buffer++ = v;
            }
            for (; i < buf_c; ++i)
                *buffer++ = 0;
        }
    }
}

int stb_vorbis_get_frame_short_interleaved(stb_vorbis *f, int num_c, short *buffer, int num_shorts)
{
    float **output;
    int len;
    if (num_c == 1) return stb_vorbis_get_frame_short(f, num_c, &buffer, num_shorts);
    len = stb_vorbis_get_frame_float(f, NULL, &output);
    if (len) {
        if (len*num_c > num_shorts) len = num_shorts / num_c;
        convert_channels_short_interleaved(num_c, buffer, f->channels, output, 0, len);
    }
    return len;
}

int stb_vorbis_get_samples_short_interleaved(stb_vorbis *f, int channels, short *buffer, int num_shorts)
{
    float **outputs;
    int len = num_shorts / channels;
    int n = 0;
    int z = f->channels;
    if (z > channels) z = channels;
    while (n < len) {
        int k = f->channel_buffer_end - f->channel_buffer_start;
        if (n + k >= len) k = len - n;
        if (k)
            convert_channels_short_interleaved(channels, buffer, f->channels, f->channel_buffers, f->channel_buffer_start, k);
        buffer += k*channels;
        n += k;
        f->channel_buffer_start += k;
        if (n == len) break;
        if (!stb_vorbis_get_frame_float(f, NULL, &outputs)) break;
    }
    return n;
}

int stb_vorbis_get_samples_short(stb_vorbis *f, int channels, short **buffer, int len)
{
    float **outputs;
    int n = 0;
    int z = f->channels;
    if (z > channels) z = channels;
    while (n < len) {
        int k = f->channel_buffer_end - f->channel_buffer_start;
        if (n + k >= len) k = len - n;
        if (k)
            convert_samples_short(channels, buffer, n, f->channels, f->channel_buffers, f->channel_buffer_start, k);
        n += k;
        f->channel_buffer_start += k;
        if (n == len) break;
        if (!stb_vorbis_get_frame_float(f, NULL, &outputs)) break;
    }
    return n;
}

#ifndef STB_VORBIS_NO_STDIO
int stb_vorbis_decode_filename(const char *filename, int *channels, int *sample_rate, short **output)
{
    int data_len, offset, total, limit, error;
    short *data;
    stb_vorbis *v = stb_vorbis_open_filename(filename, &error, NULL);
    if (v == NULL) return -1;
    limit = v->channels * 4096;
    *channels = v->channels;
    if (sample_rate)
        *sample_rate = v->sample_rate;
    offset = data_len = 0;
    total = limit;
    data = (short *)malloc(total * sizeof(*data));
    if (data == NULL) {
        stb_vorbis_close(v);
        return -2;
    }
    for (;;) {
        int n = stb_vorbis_get_frame_short_interleaved(v, v->channels, data + offset, total - offset);
        if (n == 0) break;
        data_len += n;
        offset += n * v->channels;
        if (offset + limit > total) {
            short *data2;
            total *= 2;
            data2 = (short *)realloc(data, total * sizeof(*data));
            if (data2 == NULL) {
                free(data);
                stb_vorbis_close(v);
                return -2;
            }
            data = data2;
        }
    }
    *output = data;
    stb_vorbis_close(v);
    return data_len;
}
#endif // NO_STDIO

int stb_vorbis_decode_memory(const uint8 *mem, int len, int *channels, int *sample_rate, short **output)
{
    int data_len, offset, total, limit, error;
    short *data;
    stb_vorbis *v = stb_vorbis_open_memory(mem, len, &error, NULL);
    if (v == NULL) return -1;
    limit = v->channels * 4096;
    *channels = v->channels;
    if (sample_rate)
        *sample_rate = v->sample_rate;
    offset = data_len = 0;
    total = limit;
    data = (short *)malloc(total * sizeof(*data));
    if (data == NULL) {
        stb_vorbis_close(v);
        return -2;
    }
    for (;;) {
        int n = stb_vorbis_get_frame_short_interleaved(v, v->channels, data + offset, total - offset);
        if (n == 0) break;
        data_len += n;
        offset += n * v->channels;
        if (offset + limit > total) {
            short *data2;
            total *= 2;
            data2 = (short *)realloc(data, total * sizeof(*data));
            if (data2 == NULL) {
                free(data);
                stb_vorbis_close(v);
                return -2;
            }
            data = data2;
        }
    }
    *output = data;
    stb_vorbis_close(v);
    return data_len;
}
#endif // STB_VORBIS_NO_INTEGER_CONVERSION

int stb_vorbis_get_samples_float_interleaved(stb_vorbis *f, int channels, float *buffer, int num_floats)
{
    float **outputs;
    int len = num_floats / channels;
    int n = 0;
    int z = f->channels;
    if (z > channels) z = channels;
    while (n < len) {
        int i, j;
        int k = f->channel_buffer_end - f->channel_buffer_start;
        if (n + k >= len) k = len - n;
        for (j = 0; j < k; ++j) {
            for (i = 0; i < z; ++i)
                *buffer++ = f->channel_buffers[i][f->channel_buffer_start + j];
            for (; i < channels; ++i)
                *buffer++ = 0;
        }
        n += k;
        f->channel_buffer_start += k;
        if (n == len)
            break;
        if (!stb_vorbis_get_frame_float(f, NULL, &outputs))
            break;
    }
    return n;
}

int stb_vorbis_get_samples_float(stb_vorbis *f, int channels, float **buffer, int num_samples)
{
    float **outputs;
    int n = 0;
    int z = f->channels;
    if (z > channels) z = channels;
    while (n < num_samples) {
        int i;
        int k = f->channel_buffer_end - f->channel_buffer_start;
        if (n + k >= num_samples) k = num_samples - n;
        if (k) {
            for (i = 0; i < z; ++i)
                memcpy(buffer[i] + n, f->channel_buffers[i] + f->channel_buffer_start, sizeof(float)*k);
            for (; i < channels; ++i)
                memset(buffer[i] + n, 0, sizeof(float) * k);
        }
        n += k;
        f->channel_buffer_start += k;
        if (n == num_samples)
            break;
        if (!stb_vorbis_get_frame_float(f, NULL, &outputs))
            break;
    }
    return n;
}
#endif // STB_VORBIS_NO_PULLDATA_API

/* Version history
1.07    - 2015/01/16 - fixed some warnings, fix mingw, const-correct API
some more crash fixes when out of memory or with corrupt files
1.06    - 2015/08/31 - full, correct support for seeking API (Dougall Johnson)
some crash fixes when out of memory or with corrupt files
1.05    - 2015/04/19 - don't define __forceinline if it's redundant
1.04    - 2014/08/27 - fix missing const-correct case in API
1.03    - 2014/08/07 - Warning fixes
1.02    - 2014/07/09 - Declare qsort compare function _cdecl on windows
1.01    - 2014/06/18 - fix stb_vorbis_get_samples_float
1.0     - 2014/05/26 - fix memory leaks; fix warnings; fix bugs in multichannel
(API change) report sample rate for decode-full-file funcs
0.99996 - bracket #include <malloc.h> for macintosh compilation by Laurent Gomila
0.99995 - use union instead of pointer-cast for fast-float-to-int to avoid alias-optimization problem
0.99994 - change fast-float-to-int to work in single-precision FPU mode, remove endian-dependence
0.99993 - remove assert that fired on legal files with empty tables
0.99992 - rewind-to-start
0.99991 - bugfix to stb_vorbis_get_samples_short by Bernhard Wodo
0.9999 - (should have been 0.99990) fix no-CRT support, compiling as C++
0.9998 - add a full-decode function with a memory source
0.9997 - fix a bug in the read-from-FILE case in 0.9996 addition
0.9996 - query length of vorbis stream in samples/seconds
0.9995 - bugfix to another optimization that only happened in certain files
0.9994 - bugfix to one of the optimizations that caused significant (but inaudible?) errors
0.9993 - performance improvements; runs in 99% to 104% of time of reference implementation
0.9992 - performance improvement of IMDCT; now performs close to reference implementation
0.9991 - performance improvement of IMDCT
0.999 - (should have been 0.9990) performance improvement of IMDCT
0.998 - no-CRT support from Casey Muratori
0.997 - bugfixes for bugs found by Terje Mathisen
0.996 - bugfix: fast-huffman decode initialized incorrectly for sparse codebooks; fixing gives 10% speedup - found by Terje Mathisen
0.995 - bugfix: fix to 'effective' overrun detection - found by Terje Mathisen
0.994 - bugfix: garbage decode on final VQ symbol of a non-multiple - found by Terje Mathisen
0.993 - bugfix: pushdata API required 1 extra byte for empty page (failed to consume final page if empty) - found by Terje Mathisen
0.992 - fixes for MinGW warning
0.991 - turn fast-float-conversion on by default
0.990 - fix push-mode seek recovery if you seek into the headers
0.98b - fix to bad release of 0.98
0.98 - fix push-mode seek recovery; robustify float-to-int and support non-fast mode
0.97 - builds under c++ (typecasting, don't use 'class' keyword)
0.96 - somehow MY 0.95 was right, but the web one was wrong, so here's my 0.95 rereleased as 0.96, fixes a typo in the clamping code
0.95 - clamping code for 16-bit functions
0.94 - not publically released
0.93 - fixed all-zero-floor case (was decoding garbage)
0.92 - fixed a memory leak
0.91 - conditional compiles to omit parts of the API and the infrastructure to support them: STB_VORBIS_NO_PULLDATA_API, STB_VORBIS_NO_PUSHDATA_API, STB_VORBIS_NO_STDIO, STB_VORBIS_NO_INTEGER_CONVERSION
0.90 - first public release
*/

#endif // STB_VORBIS_HEADER_ONLY
